Bullet "lube", Is it needed and if so -- when?

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John Alexander posted this 06 October 2018

As recently stated in the recent lube purging thread. i only use lube in for my competition bullets in the tiny gap ahead of the gas check. I sometimes do well against shooters who lube their bullets from stem to stern and sometimes not so well, but it seems this vanishing amount of lube is best for my loads.

Looking at one of these bullets it is hard not to ponder that if such a tiny amount is lube does the job, does the bullet need any at all, especially at the low velocities I shoot in competition. I decided to find out. Since I didn't want to be pulling bullets out of the remaining unfired rounds after leading up the bore, I only loaded ten cases. These were from the same batch of 85 grain bullets I fired in the recent CBA nationals and loaded to duplicate the muzzle velocity of 1,430 fps although with TiteGroup instead of 4756. Otherwise the load was the same.

I shot the lubless bullets this morning. Starting from a clean bore, and not cleaning between groups, one 5 shot group was slightly under 1 MOA and one slightly over for an average of 1.12 MOA.  This is almost exactly the same as the average accuracy of these loads with lubed bullet and this load.

When cleaning the bore the first patch went through smoothly with no hitches indicating leading or hard fouling. The patch showed no signs of lead particles.

Of course two groups is far too small a sample to draw any conclusions but I plan to shoot more.

John

 

 

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RicinYakima posted this 15 April 2021

John,

Sorry I am late to your last post, been down on the Columbia trying to catch fish in the wind. Not good.

My story is that when I first started shooting cast rifle bullets, I loaded 20 up unsized and unlubed. Just before I chambered them, I dipped the bullet and end of the case neck in Hoppe's #9. (I was trying to see if Elmer Keith was correct that #9 damp bore would not shift zero.) I was fully prepared to have some leading in the barrel, but there was nothing.  Zero was very close, and ten-shot groups were as good as an I was shooting at that time.

I lube my flintlock patches well, but only to keep the fouling soft enough I can load the next ball. 

Ric

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John Alexander posted this 14 April 2021

We don't actually know that what we need is a "lube" that stays on the bullet under pressure and heat.  That's what is needed for oils and greases to actually make thing slide better. it bullet lubes made bullets slide better on steel they should go faster than unlubed bullets -- and they don't.

Maybe what we need is something that vaporizes off the bullet in the right conditions and forms the right type of weak surface layer in the bore. Or something else. Or maybe we don't need anything at all for many conditions , a possibility that CB shooters apparently don't want to think about. You can ignore this elephant if your want to but you also have to ignore that many good bullet lubes are terrible at making things slide better.

Difficult to remove bullet lubes wouldn't bother us if we didn't use them.  But the ol' boys shooting black powder used them so they must be needed, and except for the folks in the posts above who have tried it, we apparently aren't curious enough to find out. Oh well, it's just a hobby.

John

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Bud Hyett posted this 14 April 2021

On the subject of lube removal. Observed that I wasted too much time that could be used producing better ammunition after learning from a mistake.  After trying all of the above ways to remove lubricant in the last four decades, I've adopted this two-part rule:

  • Has a gascheck - Goes down the barrel for practice.
  • Does not have a gascheck - Back in the pot to melt  

After all, we choose a lubricant for the ability to stay on the bullet under pressure and heat. Why would it be easy to remove? 

Farm boy from Illinois, living in the magical Pacific Northwest

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OU812 posted this 13 April 2021

I use my old lyman vibratory to tumble fresh cast bullets. It only takes about 10 minutes. Be sure to rinse bullets in HOT water to remove sand and static electricity. Static will repel powder.

As far as removing wax from bullets, i've never had to do that, so i do not know. Maybe boil bullets in water so wax will float to top and be skimmed off, then tumble in sand? 

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mashburn posted this 13 April 2021

Hello OU812,

After reading your post about tumbling in sand, I had a job to try it on. Years ago before I started powder coating I had a very large number of cast bullets that were sized and lubed. I decided to take the lube off of them and powder coat them and man was that a mistake. I've tried everything from soaking in lacquer thinner and washing in hot soapy water, all to no avail. After those attempts, I tumbled them in Walnut media and that didn't work either. The lube that was on them is Zambini Rooster Red. After a lacquer soaking it just leaves a thin greasy coat of lube on them that turns white instead of staying red.. Have you got any more ideas of how to get the last of the lube off of the bullets?

After trying the sand tonight I will definitely use it, in the future, when I have a batch of bullets that aren't taking powder well.

Thanks:;any suggestions would be appreciated

Mashburn

David a. Cogburn

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OU812 posted this 12 April 2021

I will try a 223 test using your shortened bullet and post results this will take a few days.

Wad up the none stick aluminum foil then un ravel before covering baking pan. This will leave raised areas so there is less surface for bullets to bake. Just dump the bullets onto pan and bake. No need to try and stand those little bullets on their bases.

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John Alexander posted this 11 April 2021

OUB12,

Good suggestion and I have saved your quick instructions and put that suggestion on my to do list. But the list is pretty long.

I believe several others on this forum including you are in a much better position than I am to make that comparison.  We got quite of test results into the forum during the early part of this thread.  I hope we can encourage others to do it again.  How about it you PC vets?

John

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John Alexander posted this 11 April 2021

Five shot groups give more information than ten shot groups FOR THE TOTAL NUMBER OF SHOTS FIRED and seven shot groups are slightly better yet. Calculating the mean radius gives still more information, for the total number of shots fired, (this is not the same as string measurement). Mathematicians have proven these things so they are not open to our opinions about how it seems, how it feels, or common sense. 

If I understand, Ken's suggested refinements of the mean radius method, they would give yet more information for the number of shots fired.

As an engineer instead of a mathematician I argue that the best practical measure, for the total number of shots fired, in spite of its drawbacks, is the AVERAGE of five shot groups.

They are quick and easy to do and easy to understand.

They are used widely thus allow easy comparison with other results from competition and other precision shooting.

There is less danger of shooter fatigue causing a bad shot than hurrying  through a 10 or 25 shot group before conditions change, which are mathematically less efficient anyway. And if there is such a shot due to fatigue or condition change it affects the average less.

Averages of five shot groups usually correlate well with the more elegant but more time consuming mean radius anyway so you don't gain much.

I think that to get closer to the true (unknown) precision of a rifle, load, shooter, combination, time is better spent shooting more shots than spent finding the coordinates of fewer shots and plugging them into a computer. (That my computer has been giving me trouble may be affecting my judgment at the moment.)

Shooters are constantly making  decisions while "working up loads"  based on two group comparisons. This is simply kidding ourselves, as is most "ladder testing".

John

 

 

 

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OU812 posted this 11 April 2021

Tumble bullets in sand, rinse in hot water, dry in oven @200 degrees, tumble in powder, put back in oven @400 for 15 minutes.

The course finish of tumbling in sand helps powder to stick better.

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OU812 posted this 11 April 2021

John, Do a test of unlubed vs powder coated. Please post your results.

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Ken Campbell Iowa posted this 11 April 2021

a few years ago Jim Scearcy mentioned he had put together a spread sheet that 

if you input the xy co-ordinates ( from any starter reference point .. lower left being good ) ... it would regurgitate the mean radius and also create a visual graph showing the group.  then you could store your target file in your computer for record.

pretty cool ...  fun to play with it using my free Office Libre ... i added standard deviation of the location of the shots, which is only interesting for describing the " scatterness " of the shots ... and i added a calculation of * group size * which turned out to be not so easy as you might think  ... makes you appreciate the human eye and mind ...  think of it as compared to writing a program on how to tie your shoes ...

**************

anyway, to establish the center of the group we took the average " x " co-ordinate and the average " y " co-ordinate of all the shots and that is the xy co-ordinate of the group "center" .

the above is just for fun, i suppose there are dozens of more complete free target analysis apps out there.

ken

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Ken Campbell Iowa posted this 11 April 2021

i always thought group shooting was like "  what is the worst that can happen ? .   " ... might be useful for shooting cigars out of someone's lips ... you wouldn't want a 6 inch group ...

i always thought * mean radius * would describe rifle QUALITY better ...  i think this is what Tom G. was describing.

this is because if :: out of 10 shots, 9 go into the same hole and one zings off two inches... the QUALITY is better than if the 10 shots create a 2 inch diameter circle.

if you are shooting at 10 starlings sitting on a telephone line ( remember those ? ) ...with the first load you would hit 9 and miss one ... with the 2nd load you might miss all 10 ...  

which load has higher QUALITY ?

( notice i don't say * accuracy * because i don't know what that means.

*****************

Joeb cautions me that i might be wrong because of the commonality of information ...  and so i use " thought " instead of " know " ... heh ...

ken

 

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45 2.1 posted this 11 April 2021

That is what the military over 100 years ago used to evaluate trapdoor loadings among other things. It's called string measure which is used to get mean radius.

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ray h posted this 11 April 2021

Would firing 25  single shots groups and measuring distance from a small aiming point on each be better, Barrel temp, fouling etc, even shooter error could be factored into the overall group. ???

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Tom G posted this 11 April 2021

Hi John, 

I applaud you for your continued work in trying to evaluate the ways we gage the accuracy of our cast bullet shooting. Your last post piqued my interest in the subject again. For some reason, I recently was thinking of how we evaluate our level of precision and if we are on the right track. For reasons of competition, we measure 5 and 10 shot groups and gage the quality by measuring the two furthest shots from each other. That seems to work to a degree and is probably the best way to conduct a competition within the constraints of time etc. to have a match.  But the question arises as you have pointed out; What is the best way to measure the actual performance of our gun/load/shooter?  Should we or should we not include fliers or outliers. If so, how much weight should be give to them in establishing the overall accuracy of a load? 

In the lost paragraph of your last post, you mention ignoring or throwing out the outlier shots in some of the groups we shoot in gaging the quality or "true accuracy" of a load. You bring up a good point on what to do with the outliers  or fliers in a group. My opinion is that we need to always include them in the calculations. Using the two widest shots method of evaluating groups or average accuracy is not, in my estimation a good way to include the outlier shots. 

First, I believe that shooting 5 and 10 shot groups and then averaging them together is not the best way to evaluate the overall accuracy of a gun/load combination. i suggest that a better way is to shoot all the sample shots into the same group and increase the sample size. Increasing the sample size increases the percent of confidence of the conclusions made from analyzing the group.  

Many years ago, I'm almost 79 now, I was working for Ford Motor Company as a Quality Control Analyst. Part of my job was to evaluate the quality levels of production operations for compliance with the established dimensional tolerances of the component parts and completed assemblies. I routinely had a person go out into the factory and take a sample of a part or assembly and gage all of them and record the data. I would then take the data and run it in a computer program that broke down the distribution of the recorded dimensions and basically put them into a bell shaped curve and predicted with a certain level of confidence what the larger population of parts would fall under as far as how many percent fell within the tolerances allowed on the design drawings. 

We were dealing with a stack up of tolerances when we started assembling a bunch of parts into, let's say, an engine distributor,  We knew that over 99% of the parts would likely fall into an acceptable range and work well when mated to other engine parts. We also anticipated getting the occasional "outlier" that due to a stack up of too many max dimension parts would end up too big or the opposite, too small. The sample size was in the range of 250 samples and that yielded a percent of confidence that was in the very high 99 % range. In other words, the result of analyzing the data could be expressed as " I am 99.6 % confident that 98,2% of the parts will fall within the design limits". Or something like that. I'm pretty sure that now, 50 years later, they probably do it a little different.    

With that in mind, I feel that what we are trying to accomplish is much the same in measuring the accuracy of a load on paper. In the above example, we measured every part. We didn't throw out any part that was outside the core group of dimensions. In measuring the quality of a group, we need to include all the fliers or outliers in the group as part of the group. As you mentioned, we could throw out some percentage of outliers as unexplained fliers and grade the group without them. But that would be ignoring science in my humble opinion and distorting the actual data that we collected. Let's face it, they were part of the group and we need to find a way to include them in the calculations for the quality of the group. 

If we look at extreme spread of a group, we find that including the outliers in it really distorts the level of quality of the group excessively and that's not acceptable. 

I'm thinking that a better way of evaluating the group size is to shoot all the shots into one group. Use a sample size of say 25 shots instead of 5 five shot groups. Include all shots in the analysis and not throw out any fliers. Find a way to establish a reference point in the group and then measure the distance each shot is from the reference point. Add up all the distances and divide by the number shots shot. The result would be an average distance from the reference point. Use that as the quality level of the group. 

If we could find a way to establish the average center of the group, that would probably be the best way to establish the reference point from which all shots are compared. That way, an outlier shot would have no more effect on the final calculated quality level of the group than any other shot would have. 

I've seen similar methods like this for evaluating groups in the past. Keep in mind that this method is just giving us a level of dispersion from a central location, not how well the shots fell in relation to an intended point of aim. In other words we could say we are looking at the consistency of the rifle/load to put a certain number of shots together in one spot. I think this method or one similar to it would allow us to include outliers in the calculations as they should be without giving them more weight than they deserve.  It seems to me that a method such as this would tell us with more certainty how well a certain load is doing in relation to other loads. 

Just my $ 0.02 worth.  

Tom  

 

 

 

 

 

 

 

 

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RicinYakima posted this 11 April 2021

John,

I don't know either, so it will be up to you and Joe to figure that out. All that math hurts my head and makes me dizzy. 

Having shot benchrest for over 25 years now, true flyers are rare for me. If the hold is good and the trigger is good, it isn't a flyer. You have convinced me, so maybe you can get other folks to look at this from a bigger picture. Following along on your writing has changed my point of view a lot. 

Ric

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John Alexander posted this 10 April 2021

Ric,

I won't argue that point. But you are preaching to the choir.  I have written at least two articles (and have one more partially written) trying to convince shooters that almost all of what CB shooters call fliers are just part of a normal group or natural outliers (one shot has to be the worst shot  except in a perfectly round group) and not an indication that there was something wrong with that particular shot.  So I won't argue about those two shots which by the way both increased the groups they were in by 126%. It will be awhile before that happens again.

However, for the best estimate of the true accuracy, I will argue that at SOME percentage increase of the best four (or nine) shots you should disregard a shot as not representing the rest.  What that percentage is I don't know. 

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RicinYakima posted this 10 April 2021

John,

I don't think those farther outside of core shots are errors of shooting or reloading. I think that they are just the natural outliers of a normal group. So, in my opinion, they should be calculated into your averages. 

Ric

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mashburn posted this 10 April 2021

Hello Jeff,

 I think you just hit the nail, square on the head with the idea that the small charges don't erode the bullet.

Mashburn

David a. Cogburn

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John Alexander posted this 10 April 2021

The results of the shooting reported in this thread resulted in an article in TFS #264. 

The results for the paired groups of lubed vs. bare bullets were as follows:

 

 

                                                         Lubed              Unlubed               Increase

 

Springfields (24 ten-shot groups)        1.96”               2.17”                       11 %

 

Tikka (26 five-shot groups)                 0.99”               1.00”                          1%

 

These results indicate a possible modest increase in group size for unlubed bullets for Carlson’s equipment and loads and an insignificant increase for my equipment and load. 

 

Reading this thread again to refresh my memory inspired me to pick up the subject again since the results of all these groups by several shooters hadn't answered some of the questions asked.  So more recently, I fired an additional series of paired groups in the same rifle and with the same load, except CCI pistol primers were substituted for the Winchester small rifle primers with the following results.

 

Tikka (10 five-shot groups) --- lubed bullets = 0.89”, bare bullets = 0.84”, --- 6 % smaller.

 

However, each of the string of groups had one shot that more than doubled the size of its group. It is arguable whether such shots should be disregarded as not representing the true accuracy.  But if these two are disregarded the results change a bit.

 

Tikka (10 five-shot groups) ---lubed bullets = 0.79”, bare bullets = 0.71”, --- 10 % smaller.

 

However, if all the 36 five-shots in the Tikka so far are averaged together the combined results look like this.

 

Tikka (36 five-shot groups) --- lubed bullets = 0.947”, bare bullets = 0.930", ---- 2% smaller.

 

Although the ten additional groups by themselves seemed to provide a weak indication that cast bullets may shoot better unlubed, even that weak indication disappears when all the shooting so far is considered.  On the other hand, the evidence so far that lubing cast bullets improves accuracy is equally weak and provides no no evidence to justify the extra work of lubing bullets.

 

I intend to continue shooting pairs of comparison groups of bare vs. lubed bullets to try to see if bare bullets may perhaps reduce fouling and provide a more stable bore condition. I hope other curious shooters will shoot strings of comparison groups to see what we can learn.

 

John

 

 

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