Hocus pocus....

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ssgt posted this 06 December 2006

I would like to hear some opinions on bullet lube.

Do yall really think its that mysterious, eye of newt, bat wings and snake blood? Ive used alot of different lubes and my experience is that its not that complicated. My rifle loads are almost always full speed loads, actual rifle powders. The fastest thing I use in rifle loads is 2400. And handgun loads, Ive even used vaseline on some of those just for the heck of it. Whats yalls thoughts on this? Am I going up against a “sacred cow” here or am I too simple minded? This isnt to say that anything will do, even I have certain requirements lube must meet, i just think its overly complicated when it doesnt need to be.

Ed Harrison

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CB posted this 07 December 2006

This is a pretty good question and to tell you the truth I don't know the answer. I always just assumed the people that put out the lubes knew what they were doing and didn't think about it one way or the other. One thing I do believe that lube is just what the name implies and nothing else. There's opinions that the lube is a gas seal but I don't understand how when a lot of the same people that think this also believe that leading is caused by hot powder gasses flowing past the bullet melting and depositing lead ahead of it as it travels down the barrel. If the hot gasses would melt lead it would for darn sure melt lube.

When it comes to lube I think Veral Smith hit the nail right on the head when he wrote in his book that leading is caused by bullet obturation overcoming the lubes ability to do its job. In other words match the BNH strength to the load, fit the bullet to the bore, and use a lube with the properties and in the amount to get the job done.

Maybe with the right load encompassing the right BNH strength, pressure, and a host of other variables, you might be absolutely correct that anything with lubrication properties would work but since I don't know and always just went with the flow I can't say. 

                                                       Pat 

 

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CB posted this 07 December 2006

Now this might not be 100% accurate, but it is as I understand it. First you need to have a properly fitted bullet, one that fills the lands completely. That is the reason some people shoot a .311 bullet out of a .309 land diameter gun. The lube is there to assist in lubricating the bullet as it travels down the barrel as it's first job. The second job is to put a coating on the inside of the barrel so if in the event that some hot gas leaks past the gas check and melts some of the lead, that it will not adhere to the barrel. There is a difference between shaving lead off of the bullet and leading. Leading is the condition that occurs when the lead bullet acutally vaporizes and aheres to the barel. Shaving is what occurs when you push an oversized bullet into a bore that is smaller than the land diameter. Shaving will present itself as small thin flakes of lead on the cleaning patch. Leading will present itself as a grey smudge or possibly a larger flake of lead on the cleaning patch. Many think that using a synthetic lube is better because it is not prone to burn as easily as natural components found in other lubes. Many also think that a bullet should retain the lube down to the target. Some think that the lube should 'spin off' the bullet upon muzzle exit. Again bullet strength is critical when choosing a load. It your bullet strength is lower than the appropriate powder charge, then your chances of hot gas leaking past the GC is very high and leading may occur. You should always consider bullet strength first when selecting a load, just because you can push it 2500 fps doesn't mean that is where it will be most accurate. Lube choice is a matter of personal preference. Read some of the posts under what bullet lube to you like best in this forum.. You will see people shooting the old NRA foemula 2400 fps and better. Just my .02 worth.

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CB posted this 07 December 2006

ssgt,

I think the cast bullet lube manufacturers nudge that 'hocu pocus...' thing along for a selling point! You may be right about using about anything for lube, but different features in some lubes have a purpose to certain applications.

As Jeff commented about the lube's residual affect left in the bore, probably has more of an impact, more than anything. The components of black-powder lube's, residue helps keep the carbon fouling soft for continual shooting up to a point.

Lubes suggested for pistols are usually intended for a slower velocity and pressure, and in most cases, ease of application. In today's high tech world of pistols or handguns, the term has surpassed its original basic definition to now include all types and variations from revolvers in target grade configuration, up to high velocity magnums, to single-shot handguns practically shooting high-power rifle velocities and performances. So speaking about handgun lubes now is a loose term at best, prompting a consideration for each individual's application. Notably, your Vaseline application, or even spit would probably work for gallery loads in a revolver.

I'm not an design engineer, but I don't believe cast bullet lube actually lubes the bullet. If that were the case, the lube ring would be at the front of the bullet, not at the back. So the ingredients in cb lube does not pertain to how slick the bullet is sliding down the bore; but to the lube surviving the high temperature/pressure environment of each shot.

That remaining residual affect in the bore is most evident with the shooters using NRA Formula Alox 50/50. The many that I know who use it most commonly never clean their bore, or their accuracy will fall off considerably, until they have shot at least a handful of fouling shots down the bore again. The lube I happen to use does not do that, and I keep a clean bore at my bench, because a clean bore shoots the most accurate loads for me.

Wingnut

 

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CB posted this 07 December 2006

One thing I failed to say in my last post. Just because that is how I understand it means that is what I have been told by experts in the field. I do agree with Dan that if the lube where to provide lubrication for the bullet, there would be a lube groove at the front end of the bullet. Some bullets do have this, Lyman for instance.

However lead itself under pressure is a lubricant. .22's dont have lube on them.

The lube I use is not a pure synthetic, it has a single natural ingredient, carnuba wax in addition to the synthetic ingredients. I think the carnuba wax helps keep the amount of residue from adhering to the barrel. I too like to keep my barrel clean at the bench, I get my best accuracy when it is clean to lightly fouled.

Proper bullet fit is the most important aspect, then the lube choice comes into play. That is the mystic of this sport and also the challenge, figgering out what is gonna work for you.

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ssgt posted this 07 December 2006

I certainly feel that a good lube is better than a bad or no lube, but after all these years I still have a hard time defining just exactly what constitutes a “good” lube and what level of importance to place on it. Is it as ,less than or more important than ,say, bullet fit or barrel condition?

We all, myself included, have certain requirements for lube....mine?

1- Elasticity- I guess you could call it stickiness but I thing its more than that.

2- Heat Resistance- Im not sure what the overall importance of this is but its my OPINION that this may aid in its ability to withstand pressure, certainly cant hurt!

3- Pressure Resistance- This is a biggy to me. I think its also something that is most affected by things like bullet fit, barrel condition etc.

How does all this stuff intertwine or does it? Level of importance? Hmmm....:?

Ed Harrison

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CB posted this 07 December 2006

I believe it is all intertwined.

A lube that doesn't stick to the bullet won't do you much good if it isn't there when you need it most. But I don't want it sticking to my fingers when I bump it if need be.

I want the lube to be able to melt enough to coat the inside of the barrel. I think that is extremely important!

It HAS to withstand pressure. I am not exactly sure how much pressure is on the bullet in front of the gas check, but I am sure there is at least 20k psi behind it.

Many of the lube formula's (I make my own) I use are fully synthetic. The components have the attributes I want in a lube. High melting point (above 140 degrees F) High pressure resistance (because I use a base element that is a high pressure lube) Sticky, Soft enough to be used without heating the lubersizer and spin off the bullet on muzzle exit, firm enough not to come off on your hands, doesn't require chilling so the lube doesn't come off on hot days, doesn't cause build up after a few shots and is easy to clean out of the barrel. Color and smell mean nothing to me, I don't care if it smells good or is pink or green or blue.

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CB posted this 07 December 2006

I've read everything about cast bullets I could get my hands on during the years and still think Veral Smith has it right when it comes to the purpose of lube. The way he describes it is that you have to think of a bullet as a stack of boxes with the maximum pressure being delivered to the bottom box, or the base of the bullet, with pressures decreasing as you go towards the top of the stack, or the front of the bullet. This explains why the lube grooves aren't on the nose of the bullet. I also think he has it right that leading is caused by the bullet obturating so that the pressure against the bore overcomes the lubes ability to to do it's job. This might not be the best explanation of what I'm trying to get across and I'd heartily suggest getting a copy of Veral's book to let him explain it but I think you get the idea and I still think lube does exactly what the name says, lubricates.  

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CB posted this 08 December 2006

ssgt,

I think you're beginning to see those mystic attributes of cast bullet lubes and why the there is so much Hocus pocus..... to solve the problems of cast bullet lubes.

The surest solution to the problem would be to eliminate the lube.  It has been tried before, and I assure you, it will be tried again (wish me luck. Jeff).

Wingnut

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ssgt posted this 08 December 2006

Dan Willems wrote: ssgt,

I think you're beginning to see those mystic attributes of cast bullet lubes and why the there is so much Hocus pocus..... to solve the problems of cast bullet lubes.

The surest solution to the problem would be to eliminate the lube.  It has been tried before, and I assure you, it will be tried again (wish me luck. Jeff).

Wingnut

Now this should be very interesting! Keep us informed.

Ed Harrison

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CB posted this 08 December 2006

Actually we have been doing some research on that as well. There is a pistol bullet company that puts a coating on the outside of the lead bullet that appear to be impervious to heat and is slicker than greased lighting.

One of the fellows I shoot with (BTW a past national champion) who doesn't want his name to be known is working on this problem now. There are several companies that make such coatings and he is working on getting the coating thickness and bullet diameter right. Maybe one day...

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CB posted this 08 December 2006

Jeff,

What's the difference between bullet lube and bullet coating?

I was talking about dropping the use of lube and shooting dry lead-alloy cast bullets. Sleeved bearings are an alloy of copper or bronze, or a Babbitt metal of some type. The lead-alloy is actually a bearing material, so it lubes itself while traveling down the the steel barrel, acting just as a sleeve bearing; alloy against steel!

The trick is, getting it to seal good before the hot blast of gunpowder combustion eats away at the lead. That is when pat i.'s reply about Veral Smith's book describing obturation takes affect. There are different grades of Babbitt material for different applications of bearings, as I understand it, in relation to speed. So finding the right alloy may make the difference.

Heck, I may end up shooting cast tin bullets! Hey, how much is silver a pound?

Wingnut

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CB posted this 08 December 2006

Check out this link, it will give ya an indication of what I am talking about.

http://www.precisionbullets.com/

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CB posted this 09 December 2006

(The trick is, getting it to seal good before the hot blast of gunpowder combustion eats away at the lead)

I'm not convinced hot powder gas has anything to do with leading and I'll give my reasons why. Take bullets cast of WW and divide them into two batches, one heat treated to 25 BNH and the other as cast at 11 BNH.  For the sake of argument get them up to 2,200 fps in a load that develops 30,000 psi. I think you'd find the HT bullet would make it through with no problem but the as cast bullet would cause mucho problems. Same alloy, same bullet, same lube, same load, only difference would be the bullet's compressive strength with the harder bullet having the ability of letting the lube do it's job by placing a film of slippery stuff between the bullet and the bore. 

Another thing that puzzles me is if it's true that hot powder gas melts the base of the bullet  then why is it that lino, which has a 50 degree lower melt temp than WW and 160 degree lower melt temp than pure lead, is able to stand such higher velocities (which I assume also means more heat) than either of the other two mentioned. Wouldn't it stand to reason that Lino would be the first one to start melting and cause the most leading problems? 

I've heard of people claim to have had unlubed bullets shoot accurately but have never witnessed it, not saying it hasn't been done. The problem I see with it is that if you use the example of a bearing to describe the bullet to bore relationship it seems that a bearing designed to withstand the forces and tolerances comparable to a bullet riding down a barrel would be designed with lubrication as one of it characteristics not only to act as a lubricant but as a coolant. Maybe with certain loads and alloys you could use Ponds Hand Cream or KY Jelly but I still think a lube is going to be a necessary part of the equation.

This is just rambling on my part and if someone can explain why I'm all wet I'll gladly change my mind but I do think there's a lot of hocus pocus when it comes to the reason for lube and what it supposedly does. Not that it really matters as long as it works and it gives people something to talk about.

                                                         Pat

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CB posted this 10 December 2006

pat i. wrote: ...I've heard of people claim to have had unlubed bullets shoot accurately but have never witnessed it, not saying it hasn't been done. ...                                                         Pat

I can shoot bullets with no lube with no leading, on demand. I fill the case with Cream Of Wheat over the powder, seat he bullet, and have at it.

Norm Johnson writes in the book that he doesn't use lube any more on revolver bullets.

I don't know what lube does, but it seems that it is NOT keeping the lead and barrel interface from galling or whatever leading is. See Ken Mollohan on leading also.

My opinion, based on experience and mostly the equipment lists in TFS and the ASSRA Journal, is that either “if it's greasy it works” or there are a wide variety of lubes that work. My vote is for the former.

joe brennan 

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CB posted this 11 December 2006

I guess one of the great things about cast bullet shooting is the differing opinions. I'm still of the school that if it looks like a lube, acts like a lube, and smells like a lube, it's purpose must be to lube.

Maybe some people can get away with not using lube, I don't know, but it seems to me that if in the 100 or so years of cast bullets if it was something that had long term merit someone would have figured it out by now. There were a lot of real smart people playing around, unfortunately I'm not one of them.

                                            Pat

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ssgt posted this 11 December 2006

Has anyone considered the effect of hydraulics on the bullet and lube? There has to be some.....the lube, under that kind of pressure, would if not totally liqueify certainly jell somewhat. Wouldnt this have an effect similar to the oil between a crankshaft and a mainbearing?

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CB posted this 11 December 2006

I hate to sound like a Veral Smith groupie but as far as I'm concerned he has the most logical explanation about the purpose of lube. He also says in his book that hydraulics play a major role in getting the lube out of the groove and between the bullet and the bore.  

I use the KISS philosophy when shooting cast because it's a pretty straight forward endeavour when you think about it. Fit a bullet made for the task, use a good lube, find a load that shoots, and go at it. If something sounds logical to me I'll adopt the idea and never look back, if it sounds like BS or a lot of mumbo jumbo I'll take a pass. Might not always get the right answer this way but it sure does uncomplicate things. 

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454PB posted this 19 January 2007

I'm one who has tried a lot of “hocus-pocus” home made lubes, with everything from molybdenum, STP, and mink oil mixed with varying proportions of beeswax, Hoppes #9, and parafin. Suprisingly, none where total failures, although some certainly worked better than others. I've also use the Lee Liquid Alox with success, which indicates to me that the lube isn't only providing a “seal", but....well....lubrication!

If you can use vaseline and it works, I say go for it!

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Daryl S posted this 20 January 2007

I'm with 454PB - some lubes work in rifles, while some lubes don't. This is mostly nociable in the smaller bored rifles & especially with black powder loads in the big ones. : In the .44 mag, shooting straight WW bullets, oversize, every lube I've tried from the alox/beeswax blends to Lee liquid alox to BP lube to Lyman Moly and their BP lube has shot without any leading using full power loads. My revolver bullets are sized .430", but due to the 4” barrel, rarely beat 1,200fps except in one load of H110. They weight 275gr. in SWC, plain base. : In the big big bore rifles, Paul Mathews lube works not only with black powder, but with smokeless as well. Along with that, SPG has provided the same 'protection' in a comercial lube. Lately, I've been using Lyman Moly lube, messey by hand, less so in a lube-sizer, but a good lube so far in every rifle or handgun I've used it in - no leading to just over 2,000fps and really good accuracy all wth WW metal as cast. Anytime you can hold sub 1” with 505gr. bullets in a .458, it's a well balanced, accurate load. Those cast bullets and Lyman Moly lube are shooting to the same accuracy as jacketed bullets and probably on average, are a 1/10” or so more accurate.

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4060may posted this 20 January 2007

this article made the most sense of any I have read it is copywrited http://www.lasc.us/FryxellLubeCastBullets.htm

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Daryl S posted this 20 January 2007

Yes- makes sense. Merril Martin did an article on this very topic with much the same findings back in the 90's, published in the CBA magazine. : With black powder loads, it must also keep the fouling soft as found by Paul Mathews.

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Rooster posted this 20 January 2007

Excellent, I may just stay here awhile. I currently am considering some home brew. Yes, very informative. Thank you all.

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mtngun posted this 05 May 2007

Stickiness -- yes, it's important.  Alox is sticky.  Rooster HVR is sticky.  Beeswax is sticky as waxes go.

Melting point, flash point -- ditto. 

Pressure Resistance -- you nailed it !!!!!!!

Lubrication qualities -- yes, a lube lubricates, but that's the easy part of the job.  If lubrication were the sole or most important function, we'd all be shooting Mobil 1.

Felix lube is exceptionally slippery.  I sometimes use it for case sizing or for sizing otherwise dry bullets.  Yet Felix lube is a below average bullet lube, at least in my comparison tests.

Sealing properties -- let's combine stickiness, melting point, pressure resistance and lump them together as sealing properties.    I think this is numero uno, with lubricity a distant second.

The hocus pocus is finding a lube formula that is both a good sealant -- sticky and tough -- and a decent lubricant -- slippery.

I theorize that, the more dimensionally perfect and smooth the gun is, the less critical the lube is.  Lube is a bandaid for our not-so-perfect guns and barrels.

For low velocity, low pressure loads, your choice of lube may not be critical.   One lube may give better accuracy than others in a particular low pressure load, but there may be no obvious reason or trend.  I find the NRA formula hard to top for accuracy in low pressure loads.

Yes, I have shot unlubed bullets with fair success -- decent accuracy and only minor, stable fouling -- in one cast-friendly, dimensionally correct gun, a Ruger 357 at 1200+ fps.  However, lubed bullets shot better yet, so I'm not giving up lube anytime soon.

The same gun and load gave top velocities, decent accuracy (I'm going from memory and don't have the numbers in front of me), and ZERO leading when the bullets were “lubed” with Permatex gasket cement -- the black, sticky kind.  I guarantee you that Permatex has no lubricating properties.  Don't try this in a rifle, it burns and makes a mess that is hard to clean out.  A rifle definitely benifits from true lubrication.

In general, hard sticky lubes give higher velocities and lower standard deviations than soft, slippery lubes.  In high velocity/high pressure loads, the hard sticky lubes are generally more accurate, too.  As mentioned before, that's not necessarily the case at low velocities and pressures.

Several people mentioned matching the BHN to the load pressure.  Yes, BHN matters, but no, you cannot match the psi strength of the bullet to the psi of the load pressure.  The hardest lead alloys have maybe 10,000 psi strength (common structural steel is only 36,000 psi, did you really think that your lead bullet was stronger than steel???).  Yet we shoot loads that exceed the psi strength of our bullets all the time.  If someone wants to discuss in more detail, please start a new thread, so we don't hijack this thread.

A couple of suggestions for testing lubes, though I'll keep it short since a complete discussion deserves its own thread.

-- a chronograph is the lube tester's best friend.  Shoot at least 10 shots with each load/lube over the chrono and calculate the SD, preferably as a percentage.  Use the average velocity and the %SD as a measure of lube performance.  A good lube will give higher velocities, not because it reduces friction, but because it helps maintain a good gas seal.  For the same reason, a good lube will produce lower SDs.  Note: you cannot calculate a meaningful SD with only 3 shots or even 5 shots. 

-- I strive for accuracy as much as the next guy, but it takes a whole lot of shooting to prove a statistically significant difference in accuracy.  Except in extreme cases (like when a load can't even stay on the target) I don't draw any conclusions about accuracy until I've shot at least 5 groups per load, and even then I try to repeat the test -- and often get different results the second time around.

-- Judging fouling.  I like to use my 2 5/8” wheelgun for testing lubes, because the short barrel allows me to see the barrel fouling from one end to another.  However, in longer barrels, it's really hard to judge with the naked eye, and most times I don't even bother to look.  Even the best lead bullet loads usually foul a little bit, anyway.

-- lube star.  I think the lube star is another old wives tale.  Generally, a soft lube will leave a more prominent lube star than a hard lube.  In fact, hard lubes may not leave any lube star, yet hard lubes are generally superior for high velocity/high pressure loads.

ssgt wrote: I certainly feel that a good lube is better than a bad or no lube, but after all these years I still have a hard time defining just exactly what constitutes a “good” lube and what level of importance to place on it. Is it as ,less than or more important than ,say, bullet fit or barrel condition?

We all, myself included, have certain requirements for lube....mine?

1- Elasticity- I guess you could call it stickiness but I thing its more than that.

2- Heat Resistance- Im not sure what the overall importance of this is but its my OPINION that this may aid in its ability to withstand pressure, certainly cant hurt!

3- Pressure Resistance- This is a biggy to me. I think its also something that is most affected by things like bullet fit, barrel condition etc.

How does all this stuff intertwine or does it? Level of importance? Hmmm....:?

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CB posted this 05 May 2007

Good post.

My question to you, and this is a serious question, is since you and a lot of others think the main purpose of bullet lube is to seal, just what the heck is being sealed?

"Several people mentioned matching the BHN to the load pressure.  Yes, BHN matters, but no, you cannot match the psi strength of the bullet to the psi of the load pressure.  The hardest lead alloys have maybe 10,000 psi strength (common structural steel is only 36,000 psi, did you really think that your lead bullet was stronger than steel???).  Yet we shoot loads that exceed the psi strength of our bullets all the time." 

I think what people are saying is that you match a load to the BNH of the bullet not the other way around. In reality all this is saying is that generally the softer the alloy the slower you can push it. 

Pat

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mtngun posted this 06 May 2007

Seriously, what part of gas sealing don't you understand?  I mean, none of us can see what is going on inside the barrel, but the negative effects of hot gas blowing by the bullet is well documented (NRA CB handbook, and several excellent articles by Dave Scovill published in Handloader/Rifle over the years).  In very extreme cases, the effect of gas cutting has been observed on recovered bullets.   Most of the time, it isn't that extreme, and most of the time, we can't recover bullets in undamaged condition, anyway, but circumstantial evidence  suggests to me that gas blow-by is almost always present to some degree.

The proof is not obtained by debating theory, but by comparing the performance of very slippery lubes to tough, tacky lubes.  Or by shooting unlubed bullets in dimensionally perfect situations.  And always chronographing the results (btw, here's a clue -- my unlubed bullets produced a velocity about halfway inbetween the soft, slippery lubes and the tough, tacky lubes).  I trust chronographs more than I trust armchair theories, including my own.

There is also something to be learned merely by glancing at the lubes used in matches as posted in TFS.   It used to be that hard lubes were universally dissed, but the last time I subscribed to TFS, the hard lubes seemed to be running neck and neck with the soft lubes in popularity, and gaining. 

There was also a really good lube shootout in Handloader/Rifle about 15 - 20 years ago.  By good, I mean it was a fairly “scientific” test, with gobs of data from a ransom rest, and about every lube on the market at the time.  Hard lubes generally came out ahead in that test. 

Regarding the BHN, again, that deserves its own thread, but some people have bandied about a certain formula that claims to predict the optimal BHN for a given load pressure, and claimed that this formula's result is the strength of the bullet, and further claim that any deviation from the optimal BHN is not desireable.  In particular, that it is bad for a bullet to be too hard, because it will not obturate.

The use of “the formula” as a predictor of bullet strength is easily disproven.  It's not even close.

The good results obtained with hard cast bullets in low pressure loads is easly proven (providing there is dimensional correctness).

So in other words, “the formula” as it is commonly used, is just another old wives tale. I certainly agree with you that “the softer the alloy, the slower you can push it” but if anyone starts throwing “the formula” around, I'm going to laugh at it, and that was what I was implying in my original post.  Please start a new thread on the subject if you'd like to discuss it more, so we aren't guilty of hijacking this thread.

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CB posted this 06 May 2007

What I don't understand is how can a lubricant/sealer that has a much lower melt temp. than the lead bullet that's supposedly being melted by the hot gas flowing past it seal anything. Wouldn't it stand to reason that if the gas is hot enough to melt lead it'd make short work of something with a melt temp. 3 or 4 times lower? I might be more inclined to accept that blow by was depositing lube ahead of the bullet but in that case it would be performing the job of lubrication which a lot of people don't think is it's main purpose.

I think you hit the nail on the head when you said that none of us can see what's going on inside a barrel so everything is conjecture and theory when it comes to explaining the purpose of lube.

Just My Opinion,

Pat

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Daryl S posted this 06 May 2007

I've found that trying to technically explain exactly what is going on just gives me a headache. : What I need is a lube that works in the load I want to shoot. I've found just that in 2 different lubes LBT Blue and Lyman Moly.

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mtngun posted this 06 May 2007

If there is one thing that we can agree on, it is that none of us can see what is going on inside the barrel, we can only theorize, and in the end, theory must yield to real world results.

Have you ever done a compression test on an engine?  A common trick is to squirt a little oil inside the cylinder and repeat the compression test.  If the rings are leaky, the oil will temporarily improve the seal and you'll see a dramatic increase in compression.  If the compression remains about the same, the rings are assumed to be sealing OK.

Likewise, when I switch from a soft, slippery lube to a tough, tacky lube and see a 200 fps increase in velocity -- that's an extreme case, but one that really and truly happened --  then I am inclined to assume that my “rings” were not sealing.   As with piston rings, the lube seal is a bandaid, and the real fix is good rings in a good engine.  However, in the real world, we sometimes rely heavily on bandaids.

Conversely, if the switch from a soft, slippery lube to a tough, tacky lube only produces a 5 - 15 fps increase in velocity, then I'm inclined to think “this load is sealing pretty well, so I should focus my attention elsewhere."  Those are the kinds of loads we'd like to have all the time.

"But,” you say, “maybe that 200 fps was due to reduced friction."  Fair enough.  I would reply that any cast bullet is easier to engrave and more slippery than a jacketed bullet, yet my high velocity CB rifle loads struggle to match jacketed velocities, with the same powder charge.  I would point out that the original Barnes X bullet usually gives HIGHER velocities with the same powder charge, and no one believes that the original Barnes X has a low coefficient of friction.  I would point out that the lubes that give top velocities are generally the least slippery lubes.  I would point out that my UNLUBED bullet test, mentioned before, produced velocities halfway in between the slippery lubes and the sticky lubes (repeat, that is an important clue).  And finally, I would point out that I have shot bullets “lubed” with valve grinding compound -- and you probably have, too, if you've ever firelapped a barrel -- and saw no significant change in velocity or pressure. 

If you've ever firelapped, you know that even wimpy firelapping loads warm the barrel very quickly.  Heck, even hand lapping makes a barrel warm to the touch.  So obviously, there's a lot of friction being generated.

Getting back to our lube-seal-bandaid ......  will the lube-bandaid hold forever?  Of course not, but it might last long enough to get the bullet out of the barrel.

Regarding temperature, we don't know how hot a bullet gets -- Vaughn claims he figured it out, but some of his claims are disproven every time we pull the trigger on a cast bullet -- but it is fair to say that most of the bullet doesn't get very hot, otherwise it would never reach the target. 

Ditto with plastic wads like the Neco wads.  Surely the burning powder gets hot enough to melt the plastic wads, given enough time, however, Neco wads that I have recovered downrange look practically band new, even though they were directly exposed to the burning powder for the entire trip down the barrel.

Certainly some of the lube does vaporize, but that is not necessarily the end of the world, if there is more lube to replace it. 

How, exactly, does gas-blow by screw up cast bullets?  Is is by melting?  Or is it simply by eroding with hi-velocity gas, that would erode every bit as much if the gas were cool?  Or does it create a venturi effect that actually pulls a vacuum and vaporizes the lead (don't laugh, it's theoretically possible)?  Or does a gas leak on one side of the bullet push the bullet to one side and throw it out of balance?  Or all of the above?  Since I can't see inside the barrel, and since I have no way (yet) to recover and examine undamaged bullets, I can't begin to answer those questions.

The only thing I am sure of, is there is gobs of real world evidence that suggests that lube can have a big influence on gas seal.

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Ken O posted this 06 May 2007

I don't think there is “hocas pocas", but we have different circumstances. I think the NRA 50-50 works as good as anything, BUT, its sticky, requires you to keep them separate until loaded, and even the brass gets caked with the stuff. For home plinking/target shooting this might not be a problem, but I shoot ISPC and IDPA matches. Where I shoot is all sand, picking up the cases with sand sticking to the cases, and when your running and gunning, dropping the mags, everything has sand sticking to it. The hard lubes work better for my purpose, I cast 5 to 6 hundred at a time and lube/size immediately. I lube a hundred, place them singularly on a meat tray than dump them in a box when tray is filled. I put the whole casting/lube/size session in one box. The White label works great for my purposes.

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JackG posted this 10 November 2008

mtngun wrote: Several people mentioned matching the BHN to the load pressure.  Yes, BHN matters, but no, you cannot match the psi strength of the bullet to the psi of the load pressure.  The hardest lead alloys have maybe 10,000 psi strength (common structural steel is only 36,000 psi, did you really think that your lead bullet was stronger than steel???).  Yet we shoot loads that exceed the psi strength of our bullets all the time.  If someone wants to discuss in more detail, please start a new thread, so we don't hijack this thread.

 

Au contrair, mon ami!  With all do respect, A36 steel has an elastic limit of 36,000 psi but an ultimate compression strength of 70,000 psi.  Lead alloys have have an ultimate compression strength within the range of 11,400 psi (BHN 8.0) to 46,900 (BHN 36.6).  The higher strength alloys are hard enough to shatter upon impact - good for target shooting, lousey for hunting.

I agree wholehardedly with Pat i. and the experimentation and teaching of Veral Smith.  If you are interested in more detail, I highly recomend Jacketed Performance with Cast Bullets by Veral Smith available from LBT.  Also, Modern Reloading (2nd Edition) by Richard Lee has an excellent chapter (Chapter 10) on BHN, ultimate compression strength, recomended maximum pressure (approximately 10% lower than ultimate compression strenth).  This puts an empirical number on Veral's theory of high compressive stress on the base (regressing as move toward the nose) of the bullet  It is the reason that lubrication is so important at the lube grooves near the base of the bullet.

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454PB posted this 10 November 2008

 

Au contrair, mon ami!  With all do respect, A36 steel has an elastic limit of 36,000 psi but an ultimate compression strength of 70,000 psi.  Lead alloys have have an ultimate compression strength within the range of 11,400 psi (BHN 8.0) to 46,900 (BHN 36.6).  The higher strength alloys are hard enough to shatter upon impact - good for target shooting, lousey for hunting.

I agree wholehardedly with Pat i. and the experimentation and teaching of Veral Smith.  If you are interested in more detail, I highly recomend Jacketed Performance with Cast Bullets by Veral Smith available from LBT.  Also, Modern Reloading (2nd Edition) by Richard Lee has an excellent chapter (Chapter 10) on BHN, ultimate compression strength, recomended maximum pressure (approximately 10% lower than ultimate compression strenth).  This puts an empirical number on Veral's theory of high compressive stress on the base (regressing as move toward the nose) of the bullet  It is the reason that lubrication is so important at the lube grooves near the base of the bullet.

 

And yet I regularly shoot 15 BHN gas checked cast bullets at 55K pressure in my .454 Casulls with excellent results.

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JackG posted this 10 November 2008

454PB wrote: And yet I regularly shoot 15 BHN gas checked cast bullets at 55K pressure in my .454 Casulls with excellent results.

Ouch!  My wrist hurts just thinking about it.  I assume that you are using a stout revolver.  A few thoughts:

1.)  Pressure testing of a load is done with a test barrell which is completely sealed.  Pressure performace in a revolver is going to be less because of the wheel/barrell gap leakage.

2.)  The use of 90% ultimate compression strength is a guide for finding the spot that starts to deform the bullet to help seal the base but does not limit you.  Only leading does that.

3.) A gas check may allow you to go to higher pressures.  The Veral Smith theory says that leading is caused by the breakdown of the bullet lubrication at right angles to the side of the rifleing where the friction is the highest due to radial and axial acceleration.  He states that one of the major functions of the gas check is too take a large amout of this accelerating force on to the copper sides of the gas check and transfer it to the GC shank and much reduce the force on the lead itself.  This thought flies in the face of some CB theorists who think that the gas check, only checks gas.  While it may do that, its main function is to keep the lead from melting at the rifleing/bullet interface, i.e., leading.  Under load, the deformation of the bullet starts at the base and gets less as you head towards the ogive, the major force is at the bottom of the bullet.  If gas checked, the copper can handle a lot more force and without lube.  Imagine the pressures you could go to if the GCs had 1/4” walls.  The front of the bullet would be used just as a guide.

4.) I have a Marlin 1894P (16” barrell) in .44 Mag.  I shoot a full load 310 grain gas checked cast bullet, BNH 14, 1,700 fps, 38,000 psi (a sealed barrell with no revolver leaks) with Lee Liquid Alox lube (it shouldn't work at those velocities) with great success: 2” groups at 100 yds- OK using a scope on a bench rest helps.  I think this is approaching your load with (like your load) excellent results.  When I first developed the load I was sure I would lead but after thinking about it I think the 38:1 twist greatly aids in delaying the leading as the force on the rifleing/bullet interface is much reduced when compared to a twist of say 12:1 along with the help of the GC.  This supports the VS theory anyway and works, besides.

5.)My original reason for responding is to support Pat i. in his discussions because I agree with him and to clear up the meaning of the numbers quoted by mtngun as concerns ultimate compression strength in lead alloy and structural steel.  That's my story and I'm sticking with it.

 

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R D posted this 16 November 2008

I am new here but I will put in my  $.02 worth just because of a couple of things That I haven't seen yet. This is What I think But don't know. The lube may act as a lube or as an anti flux. Either way it helps to keep the lead alloy (solder) from sticking to the steel. The lube properties will help to keep the temperature lower in the bullet. The lube may also act as an insulator so that the bullet does not pick up heat from the barrel. 

    If you have ever seen a cutting torch in use you know that a flame heats the steel but that a cold jet of oxygen does the cutting. All of the bullets and photos of bullets that I have seen that show a reduction in size from gas cutting look like the kerf from a cutting torch.  I think that if a bullet is very close to the bore in size and the pressure is high enough to force the lead into contact with the barrel the lube acts as a seal to those minor places where we don't have a perfect fit. If the bullet is not a near perfect fit (too Small) the Gas going by it will blow out the lube, cut the bullet and leave us very unhappy with the performance of the lube.

    How can a low temp lube seal high pressure gasses? Have you ever drug your garden hose to a faucet and after hooking it up and turning on the valve, had water start coming out and then had the end of the hose whip violently and make a loud hissing noise? The Gas, (air) is light and easy to move. When Gas tries to pass through a small passage it goes very fast and creates heat even while causing a cooling effect down stream from it. When a fluid is passing through the same small passage it goes at a much slower pace just like the water and air in the garden hose.  The reference to an auto engine is similar, the oil on the rings is so thin that you could hardly measure it but it seals the burning fuel gases in the combustion chambers. It does this by sealing those minor faults where the parts don't fit perfect and because the molecules of oil (fluid) are so much heavier than air (gas) they start and move much slower. If the gas moves it creates friction and makes that spot much hotter than the gas temp just like the cutting torch. If we can stop the flow of gas through these small areas that don't fit well we get a well formed bullet out of the barrel and the lube, as stated above does not have to work forever just to the end of the barrel. Also the larger the passage, the faster the gas and fluids will go through.

    I am working on a homemade lube that I have pushed to about 2600 FPS (book Vel) with a 55 gr GC bullet in a 223 rem. After 25 rounds the bore was cleaner than it was at the start and the bullet passed through 6 inches of seasoned yellow pine pressure treated lumber (solid)15 ft from the muzzle and went another 6 or more inches into the ground (hard clay). It was a quick test and as I now have blown out a knee it will be some time till I can get back to work on it. It worked as an anti flux, and as a lube. I don't know if it will be accurate or if it will store well in ammunition yet. It does show promise.

    The above I believe but the following I know. Every gun is a law unto it's self when shooting cast bullets and very minor things can have a large impact. What looks good will not always work. 2 identical guns will not shoot the same. Perhaps discussions like this will help us get closer to the truth.

    One other thing that I believe is that bullets should fit very snug in the cyl & bore and that the barrel should get tighter toward the muzzle and never get larger. A Smooth finish is good but that a mirror finish is not necessiarly better. As You can see I think quite a bit but don't know much, such is the lot of a mechanic.

God Bless all

R D

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hunterspistol posted this 16 November 2008

:coolgun:  I've used Lyman moly because it just came out about the time I started reloading. Used a lot of alox too. My thoughts run along the same lines, at lower velocity, the lube doesn't make all that much difference. I have a 22 Hornet barrel that crosses the line there. At tops, it's over 1800 fps and requires a gas check. I loaded most of it as a beginner, so the lube wasn't all that important. The bore in this 10” barrel is polished out with molybdenum disulfide and some Slick 2000 mix. It might not be lapping but, it did improve the accuracy. I've been told moly disulfide is corrosive-don't know if that's true.

Recently, I've been moving up to harder lubes used with a heat element on my lubesizer. I'm shooting a 7mmTCU that runs 1900 fps, about like a 30.06. Since I'm working on it slowly, haven't quite got it accurate to 200 yards. I think either the alloy, bullet design (changed that) or lube has something to do with it.

     I don't know if it's hocus pocus but, I'm inclined to think that a rifle bullet that takes a gas check at high velocity may need a better lube. I don't see 1000 fps as being so fierce as to require anything more far-fetched than grease or tallow, alox just smells better.  I'm going to venture that the closer one gets to 2,000 fps, the more the lube might matter- I didn't say it's a fact, though.

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Recluse posted this 01 March 2009

pat i. wrote: What I don't understand is how can a lubricant/sealer that has a much lower melt temp. than the lead bullet that's supposedly being melted by the hot gas flowing past it seal anything.

My thinking is that as the lube “melts,” it goes from a solid to a liquid. As you know, liquid under pressure can resist very high gas pressures. The liquid (molton lube) is effectively “trapped” within the lube grooves of the boolit, and as obturation occurs, the liquified lube acts as a sealant. The key is in the base ingredient(s) of the lubes being used and what their (sustained) flash point is.

:coffee:

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CB posted this 01 March 2009

I think you are right on target Recluse.. The only thing I would add is this. Some of the lube does burn or partially carbonizes. This once burned soot it what makes the seal, especially in lubes that use a base lubricant of natural oil or grease.

The difference with synthetics is that the base oil component does not carbonize or burn. A simple test can prove this and if you were to try and take a synthetic based lube and flux your lead pot with it, all you will get is a lot of smoke and a big mess in your lead pot.

In many of the bullet lube formulas floating around the internet, you will see the formula call for ivory soap. It isnt the actual soap they want from this, but the sodium stearate they use to make the soap. Sodium stearate helps bind all of the ingredients together. It also helps to raise the remelt temp of the lube and adds a thickining action to the lube.

Most of the ingredients people use for lube can burn, so if you think of it this way, would you want something that is creating the liquid seal to burn, or do you want it to not burn.. Ah, that is the question...

Another function of some ingredients that are added, and this one class of ingredient in particular, is to keep the inert ingredients and any lead from adhering to the bore.

Everyone has their own opinion as to what boolit lube does, and has been the basis of many a discussion and even arguments.

Because we can not actually see what happens, much is conjecture. That is why there are people that are materials and chemical engineers. I have had the privilege of having access to both in my line of work. With a little guidance and at a cost of a couple of lunches I got a lot of what I know from them.

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JetMech posted this 01 March 2009

Just because we cannot “see” what is happening inside the barrel doesn't mean that we cannot understand what is going on. I certainly cannot see the atomic structure of the barrel, lube, bullet, etc, but I (with alot of help from folks more learned than I) can understand the physics. And that is not conjecture. We apply what we know to achieve the desired result. There are alot of variables in every different load and rifle and while the ultimate goal is no leading and top accuracy, depending on the variables, it takes different lube properties to achieve that goal. Also keep in mind that not everyone has the same goal. One guy wants top accuracy for a 5 or 10 shot string. While his test results may show that lube “X” delivers the best results, it may not hold up if the string is extended to 40 shots, where lube “Y” delivers the goods. That why, this is still an art, rather than a science. To paraphrase Ed Harris from a different thread “We are Alchemists, gentlemen".

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CB posted this 01 March 2009

To change gears a bit can I get some opinions about what causes leading? Personally I think in smokeless neck seated loads the best accuracy and least amount of leading will come when there's most likely no obturation at all but I'd like to get some opinions.

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Fred Sinclair posted this 01 March 2009

“Personally I think in smokeless neck seated loads the best accuracy and least amount of leading will come when there's most likely no obturation at all but I'd like to get some opinions.”

 I'm with Pat on this one but would add, smokeless neck seated rifle loads having bullets of 18BHN or harder, to his load description.  

Not being a hand gunner my observations, regarding lubes, apply only to the above mentioned loads. I find that bullets cast at 18BHN and above require only minimal amounts of lube. I do rely on the “star” appearance to tell me when that amount is achieved. The “stars” are lube/powder residue. If the residue on the muzzle is excessive it is time to make load adjustments of some sort. 

 I have also observed that the residue of some powders will have a forgiving effect on the efficiency, or inefficiency, of the lube. I tend to use powders that have slower burning rates than the traditional. At the same time the slower powders can produce more powder/lube fouling build up if the bore is not routinely cleaned.

 I expect some sort of dry coating is the cure-all, we just have to find it.

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runfiverun posted this 01 March 2009

the no obduration boolit definately has it's merits. i have been re-thinking this recently since i got my 358 and it's bbl was just over 3575 in size. closer to 358. my mold saeco 245gr poured just under 359 and the only sizer i had on hand was a 358 so a daaaaang close fit from boolit to bbl. i have been working on a lube that is solid but soft and requires just a bit of heat in he sizer. it also stays like a hard putty even when cold. bout right i figured for pressure situations. now i have been pushing this boolit with from 48 to 50 grains of rl-19 and have wavered between the two for various reasons. but i have fired over 200 rounds from this combination with no cleaning of the bbl nor loss of accuracy.but after firing 40 rounds yesterday i was noticing the black in the bbl from powder fouling and the darker lube star. with just a touch of antimonial wash on the lands. was this due to lube? fit??? pressure?? 45k-50k on an alloy of 1/3 water dropped. or is this just a combination of all three. with good bbl fit, no obduration, and a lube good enough to get to the end of the bbl.

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CB posted this 01 March 2009

Well Since you all starting in on this.. Allow me to grab my soap box.

Do keep in mind that I am not plugging one lube over another here, but the facts is the facts.

I make lube as many know. My lube has almost all of the qualities RunfiveRun is working on. Yep that means it is pretty soft, but it is dryer than most. The only difference is I dont have to heat mine. It is right on the ragged edge of needing heat and in colder climates a bit if heat may be needed. Now I had a lot of help getting this lube up off the ground. I am sworn to secrecy as to the formulation. But there is some rather expensive stuff that is difficult for the average joe to buy called zinc stearate. If you take this or a similar compound called Arcrawax (used in the powdered metal industry) that can serve as the drying agent you are speaking of.

As for the leading that Pat is asking about. I think there are 2 types of leading that occur. One comes from pushing a boolit past the strength of the alloy and that results in stripping the boolit past the rifling. The other is melting caused by leakage past the gas check and the lube. Of course you can have a very rough bore with pits that cause a scrapping type leading I see in some of the not well taken care of military guns.

At least that is my opinion.

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Recluse posted this 02 March 2009

Jeff Bowles As for the leading that Pat is asking about. I think there are 2 types of leading that occur. One comes from pushing a boolit past the strength of the alloy and that results in stripping the boolit past the rifling. The other is melting caused by leakage past the gas check and the lube. Of course you can have a very rough bore with pits that cause a scrapping type leading I see in some of the not well taken care of military guns.

At least that is my opinion.

I'll agree with all of the above, and even take it one step further regarding the melting theory of leading.

First, I do agree that inferior lead--be it BHN hardness, composition, impurities, etc--will degrade itself when subjected to pressures encountered inside the bore. Add a pitted or rough barrel (of which I have have a few. . .), and leading is 100% inevitable. About all you can do with a good lube is try to coordinate with a proper primer/powder charge to minimize leading.

But you're still gonna get it.

As far as the melting theory goes, I'm right with it. However, my big question and quest for knowledge is why and where does the melting occur.

If the melting comes very early on in the barrel, it's pretty safe to assume that accuracy goes the way of a political promise during an election year.

But if the melting comes towards the end of the barrel and you have a basically clean barrel at the outset of your shooting, it's been my experience that your accuracy doesn't suffer nearly as much for your first few shots. When hunting, I rarely get more than a couple of shots a day for most outings. Back at camp, I clean the gun thoroughly, eliminating any fouling/leading.

What I'm working on with my own lube development is to formulate a lube that when it liquidizes, it forms a barrier to the gasses that result from detonation of the powder. That barrier also needs to absorb some of the heat to better protect the base of the boolit. Gas checks definitely help in a big way with that, but I want additional protection for the checks and subsequent boolit.

This is where I believe that the super-grade lubricants and hybrids and full synthetics ultimately prove superior. Their viscosity is unreal and they simply do not break down the way conventional mineral oils do.

A chemist at the old Phillips Petroleum refinery once told me (and don't know if he was right on or full of fertilizer--I'm definitely not a chemist) that pure heat was a mineral oil's worst enemy. Seems kind of basic to me, but this was a long time ago when I was first getting into the black art of boolit casting and wondering out loud about lube formulas.

I do remember some impressive demonstrations when I worked on the Mobil 1 (advertising) account. They sold me on synthetic motor oil, and I've used nothing else in any of my cars or other vehicles for the past fifteen-plus years.

Bottom line is I believe that leading (other than that from inferior alloy or less-than-smooth barrels) is a result of the gases getting past the lube and damaging the forward end of the boolit as it travels down the bore. If anyone can develop a lube that will both form the correct, gas-impervious seal, plus lubricate so that whatever alloy sloughs off, then we can probably see leading cease to exist with properly formulated loads.

So do I believe in Santa Claus or what?:)

:coffee:

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CB posted this 02 March 2009

I would suspect that the leading due to pressure leak past the gas check and lube would occur at the point of travel down the boar where the peak pressure of the load occurs. If a bore shows erosion in the first 6 inches of the barrel, I think that is the area of peak pressure. Now the question, is this first 6 inches of the barrel where the gas check and lube become compromised and the leading occurs from that point on, or is there something else that is going on that I am not thinking about?

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CB posted this 02 March 2009

Anyone else have any ideas about leading and lube?

Question about the sealer theory. How do bullets that have a coating like the Hornady pistol bullets work?

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JetMech posted this 02 March 2009

Jeff Bowles wrote: I would suspect that the leading due to pressure leak past the gas check and lube would occur at the point of travel down the boar where the peak pressure of the load occurs. If a bore shows erosion in the first 6 inches of the barrel, I think that is the area of peak pressure. Now the question, is this first 6 inches of the barrel where the gas check and lube become compromised and the leading occurs from that point on, or is there something else that is going on that I am not thinking about? Given a smooth, consistant bore from throat to muzzle, your reasoning seems sound. There's a variety of reasons for failure in the first 6 inches. Under-sized bultets, mis-aligned cartidge (bullet) with the throat/bore, bullet jumping to the rifling before the powder charge is fully ignited (caused by hot primers or position-sensitive powders). What else is going on there?

As to the peak pressure question, I would ask that generally, the most accurate load will yield a pressure curve that is on the downward side of peak at the muzzle so there is the least disturbance as the bullet exits the muzzle? And also, isn't leading at the muzzle due more to velocity exceeding the capabilities of the alloy? Even in loads that peak pressure is reached rapidly, say in the first 12 inches of barrel, you can still get leading at the muzzle end if velocity is too high.  I've never had a load that leading started in the middle of the barrel. It's either at one end or the other.

One thing about lubes. I was taught that the lube should turn to a liquid state in the bore, because liquids are generally considered to be incompressable, while solids are not. How that comes into play during the bullets travel down the bore, I'm not quite sure. You guys have a great thread going here. Alot of intelligent thought being put down.

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CB posted this 02 March 2009

I have often thought that if one were to instrument a barrel with thermocouples and strain gauges from chamber to muzzle, and have a data recording unit and take say 250K samples per second, do a complete dimensional analysis and look at the bore with a highly magnified borescope and then correlate the image to the DA and instrument readings, I bet we would have a very accurate look at what actually happens.

But that is a fantasy and not very practical for the average Joe unless he hit the lottery.

There are many variables as you state Bill, I am impressed that you thought of the cartridge mis-alignment. When I shoot competition in production class where we can not change the chambering to correct such an issue, we seat the bullet only by as much of the gas check that will hold the bullet. When we size, we size to the freebore dimension which is the area between where the case ends and the rifling begins. Some of us re-throat the lead into the rifling and then taper the bullets in a special press. This helps correct that condition, but does not solve it.

I do not get any leading in that rifle, I am sure the over kill on strength of the bullet, coupled with the lower velocity (1800fps) very high quality lube and a fire lapped bore help make that possible.

Now I have seen where the bore diameter is not consistant from breech to muzzle, in fact the rifle I speak of has a new factory barrel because the old one (less than 1000 rounds) had a tight muzzle and did lead and the accuracy was terrible. But that was a mechanical problem with the rifle, it actually shaved lead and left lots of little strip like flakes on the patches.

I am very confident that if you had the proper bullet strength, barrel twist, good lube and mechanics of the weapon, you can drive a bullet over 3000fps with out leading. In fact I have seen it done.

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R D posted this 02 March 2009

Good day    I have been following this thread and find it very informative. I have used cast mostly in magnum revolvers and have noticed something and am wondering if others have seen this also or am I just seeing shadows. It seems that when using my cast bullets that are mostly just wheel weights that have a little tin added I get leading unless I keep the pressure near the top. That is I adjust my powder choice to give me near max pressures when I get the velocity that I want from mild target to high speed loads. I have had times when increasing the powder charge has eliminated leading. The theory I have is that the bullet must be forced into an intimate contact with the cylinder and barrel in able to stop the leading and that low pressures for the velocity will not force this condition. I have had guns that would not do as described above and got rid of them. I do not know about the dimensions in them as at that time I swapped until I found a good shooter instead of changing the load to match the gun. I have always sized the bullets to at or slightly above the bore size. With commercial swagged bullets I have also noticed this trend at lower pressures. I have tried to learn as much as I could about cast bullets and found a lot of contradictory information from the experts. The fit seems to be more important than the lube in preventing leading and a good hard kick to get it started is required to get the fit. Am I seeing something important here or have I smelled too much gun powder?

Rodger

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CB posted this 02 March 2009

Are the bullets sized to the diameter of the throat in the cylinder? Sounds to me like they may be a bit small and the increased pressure obdurates the base enough to seal it in the throat/barrel.

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R D posted this 02 March 2009

Jeff;  they probably were as I was sizing to the barrel dia. My experience was a while back and I am just getting back in, Life happens.

Rodger

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Recluse posted this 02 March 2009

The fit seems to be more important than the lube in preventing leading and a good hard kick to get it started is required to get the fit. Am I seeing something important here or have I smelled too much gun powder?

Based on my experience, it seems to be about a 60/40 ratio--with proper fit being the 60% factor in reducing/eliminating leading, and proper lube being the remaining 40%.

However, integrally they go hand in hand and are inseparable. I've tried casting to bore size, casting to bore plus 1/1000 up to 3/1000 over, and a variety of alloys then working a corresponding combination of charges and then shooting with NO LUBE.

Got leading every single time with the moderate to higher velocities.

I then took the same loads and configurations with boolits I had lubed. On about half the loads, I used three different configurations of a tumble lube. One was straight LLA, one was LLA cut about 50% with mineral spirits, and the third was half and half LLA with JPW, then cut about 10 to 15% with mineral spirits. With that last configuration, I always have to take the heat gun to the LLA bottle to get the mix warmed up enough to tumble thoroughly.

For the tumble-lube configurations, according to my (old) notes, the last version worked the best--the version of half and half (which is what I call it) LLA/JPW thinned with mineral spirits.

I got .357 Magnum velocities with a Lee TL158SWC up to just under 1400fps with no leading and more than acceptable accuracy. Pushed beyond that, I encountered both leading and noticable loss of accuracy. I encountered similar results with .44 Magnum using a favored RCBS 240SWC mould.

Now, when I took the same loads and used boolits I had run through the lubesizer, things began to change a bit. First thing I noticed in the .357 magnum rounds was that accuracy fell off quicker than it did with the half-and-half (LLA/JPW) mix. However, I didn't encounter any leading.

One HUGE mistake I made was in not putting the micrometer and calipers to the sized boolits. (I wish there was a smiley face that slapped his head in frustration over his stoooopidity.)

:doooah:

Later on, I mic'd the boolits and found that they were sizing a bit too large for my bore according to the slugs I'd run through (S&W Mod 686).

Rather than buying a new (RCBS) sizing die, I simply went with the TL158SWC boolits tumble-lubed. In all honesty, I don't shoot a lot of cast magnum stuff. Sacrilege and heresy notwithstanding, I still prefer jacketed bullets for my magnum loads.

But now, my interest is piqued with a couple of new lube formulas I've been working on for the past year or so.

No doubt that size matters. But what I found out in my highly scientific testing :wnk: is that the best sizing in the world, at high velocities, will still net you some leading without lubrication. Likewise, even the best lubes will not prevent leading if the boolits aren't sized properly to the bore you're shooting them out of.

:coffee:

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CB posted this 02 March 2009

Now I am gonna really mess yer day up!

If you use a moderate strength 8-12bhn boolit and get ya one of them wad punches that Fred Cornell sells in the diameter you need for yer magnum gun, get some .062 thick type 1 PCV sheeting and punch out some wads, put them little buggers on top the powder charge and under the boolit, you can pound them boolits downrange at mag velocities..

I dont do if often, dont like recoil that darn much, but I have done it. No leading either..

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R D posted this 03 March 2009

Thanks recluse; That seems to fit in with what I had seen and what I have learned in the last few months. Now I got to get time to burn and serve. If stuff will quit breaking.

Jeff; I had been considering doing something like this but was concerned with any air space over the powder, some loads only. Sort of a gas check for flat base bullets that doesn't cost an arm and leg. I have had great results with the Lyman 358156 in the past and it had become my standard magnum bullet in 357 but with the current cost of gas checks I want to use a bullet that is ready without extras. I want a good stout load but don't want to pay for more powder than I have to or have unburned powder left in the gun. My experience and what I see in the loading manuals is that standard weight cast bullets offer lower resistance in travel down the barrel and do not give optimum burn characteristics for powders like H110, even to the point of being dangerous, and I don't want to go up to 4227.  I currently use AL-8 in 4 to 5 inch 357's and even it is compressed some but some new data shows good speed and energy with less bulky and lower charge weights of powder.  I know that it will come down to burning powder but would like as much information as possible before I start. These OP wads seem to be a good option. I even intend to try gasket material if I get into it. Like you I shoot more low power loads but if I am just out bumming around I want the good stuff. Too many years of walking beside one that had the stuff and now with new components and information I want to get it right early. And yea I know AL-8 is old technology. It falls in with blue dot, power pistol and Herco but with better results. also I am running low on it.

Thanks for your help

Rodger

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