First Keith 260s Come Off the Line

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  • Last Post 26 November 2016
Bongo Boy posted this 31 March 2015

This mold was eagerly anticipated and when it came on Saturday I started cleaning up my pest-hole of a garage in prep for some casting:

http://s182.photobucket.com/user/Bongo_Boy/media/Handloading/Keith250gr%2003_zpsxktyy2ki.jpg.html>http://s182.photobucket.com/user/Bongo_Boy/media/Keith265gr%2005_zps6g9scd9v.jpg.html>

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JeffinNZ posted this 01 April 2015

Far to pretty to shoot. Nice work.

Cheers from New Zealand

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Bongo Boy posted this 02 April 2015

I probably should just look at them because, so far, they don't shoot worth a hoot.

Naturally it's too early to make sweeping statements (isn't is always?) but with the same 800X loads I was using under the 240 gr RNFPs, I'd get tighter groups shooting 00 buck. Will have to return to the range to confirm the bad results, and I also have 50 rds of lighter loads I didn't get a chance to evaluate today.

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onondaga posted this 02 April 2015

http://castbulletassoc.org/view_user.php?id=3348>Bongo Boy

Are these for a revolver? If yes:

 Have you done the bullet  push through test with your cylinder chambers? Is your alloy strength matched to your load level? If no to either of these and your bullets push through at less than 1 pound push or your alloy is too hard or too soft for your load level , you can expect buckshot patterns on paper or even tumbling bullets. That is just the basics. Check these things before loading ammo with cast bullets for a revolver.

The bullets pictured are nice and shiny. Nice and shiny means cold cast, low diameter, and incomplete fill out. Changing your thermodynamics with a change in pot temp and a change in casting cadence can increase bullet diameter up to about +.002” when bullets are shiny and you change things to get bullets frosty instead.

A 1 or 2 cavity mold casting to drop bullets 3 times a minute is needed to maintain mold temperature for bullet fill-out.

You mention 780 F. degrees, That is suitable for pure lead or 2% Antimonial lead but way too hot for any alloy with Tin and will cause excessive oxidation loss of  your tin.  725 F. and 3 drops a minute will usually be great for bullets alloys with tin.

Gary

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onondaga posted this 02 April 2015

http://castbulletassoc.org/view_user.php?id=3348>Bongo Boy

You may also have a casting dilemma that is beyond my casting skill level. I have had revolver molds with removable nose pins that require placing the pin before casting each time and then removing the pin after each cast to drop bullets. That is a major casting cadence slow down.

I cannot cast fast enough with the pin requirements to maintain mold temperature and  get good fill-out. So, bullets will be shiny and under size, then shoot all over the place. If you wind up discovering this is your problem, what I have done to remedy that is hone the mold +.002 or sell it and get a mold that casts .002” bigger.

Gary

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Bongo Boy posted this 02 April 2015

Thanks Gary. Yes, I have much work to do, and yes, this is revolver.

The bullets before sizing are coming in at about .432 +/- .001, and I can't push them through the throats by hand with a steel pin. Multiple modest taps get them through, and they then mike at .431.

I thought I had succeeded in getting my sizing die opened up to .431, but not even close--I checked a random sample of sized bullets and to my surprise they are really averaging closer to .429 or .4295. Given the die I ordered was a .430, I'm reluctant to order a .431 only to find it's still a 1000th under. These bullets will nearly drop through the cylinder throats just using harsh language.

When I have daylight to work with tomorrow, I'll attempt to get representative photos of the bullets that have not been touched since they left the mold--they are not what I would call frosty, but they do show a little bit of character that way, not much.

As for the mold pins, there's no need to do much with them, actually. The bullets will drop without fussing with them at all, given I coax them with a gentle tap to the tongs--that's all it takes. I actually have to spend a bit of time cooling the mold after I get going, as I can pour and drop 'em far faster than the mold will cool down. I have generally aimed for a frosty sprue within 10s of the pour, roughly. Of course, running the pot up at 780F, you might expect you can outpace the mold. :)

I also use the feel of the sprue plate when I cut the sprue--if it puts up only very slight resistance, I'll usually see a shimmering bullet base (the 'wet look'), and I know I'm going to be gumming up the bottom of my plate if I keep that up. So, I get accustomed to a fair bit of resistance (I only use the heel of my hand to push that plate off, I've never intentionally waiting until tapping with the mallet was needed). I expect the bullet base to be 100% 'dry look' with no evidence of any 'wiping' of the base material.

Now, having said all that and acknowledging the bullets are sizing too small for my cylinder, still, it's surprising that the same circumstances (same lead, same sizer, same loads) seem to produce better flying bullets with the 240 grainers. But, it IS a completely different bullet so I guess that shouldn't be a big shocker.

Unfortunately, I have no way of knowing if the lead I'm using contains any tin, or anything else for that matter. I picked up some off eBay advertised as being BHN 18 (!) and thinking it might just be good stuff to work into my pot--discovering afterward it behaves a lot like it's got zinc in it. So that was a bad choice. Hard doesn't necessarily mean anything good.

Again, will post pics of the bullets as they drop from the mold--maybe that will reveal something.

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onondaga posted this 03 April 2015

http://castbulletassoc.org/view_user.php?id=3348>Bongo Boy

There is a reasonable way to test for Tin in your alloy without paying for a professional assay of your alloy:

Flux a fresh small potful of alloy at 620 F.  till brilliantly clean and shiny on the surface. Raise the temperature to over 750 F.  and wait till oxides form on the surface very heavily, about 20-30  minutes. it will be colorful. purple, red gold etc, on the surface.  Skim the colorful oxides to the edge of the pot. Now do a fiery reduction fluxing with a petroleum flux like a little oil or wax. While the flame is intense skim the oxides to the edge with a broad spoon rubbing down and against the side of the pot push the oxides well below the surface of the melt several times with the spoon bottom against the pot side. The flame is very important during this, wear a fireproof glove doing this and add more wax if necessary to feed the fire. This procedure is called reduction and will re-alloy the tin oxides as new Tin into the alloy and the oxide will disappear into alloy.

If you can do this, you have re-alloyed Tin oxide by reducing it to Tin and re - alloyed the Tin into your melt. If there is NO Tin, you cannot do this. so, doing this confirms Tin is there and at least 2% or more.

Reduction fluxing is advanced stuff to do but you can do it if you make the effort and practice the method. I routinely do it when I see colorful oxides on alloys that I cast that I know have Tin. You can put the oxide back into alloy and minimize waste of Tin that would otherwise have been skimmed off and discarded.

Actually that kind of stuff is fun for me as I am one of those guys that enjoys casting more than shooting!

I hope you get your bullets to the size that they push test at 1-2 pounds through a cylinder chamber. Then they will shoot the best for you. Bullet sizing die honing isn't physically hard but can take hours of careful methodical work and fit testing as you go along.

Gary

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Bongo Boy posted this 03 April 2015

The process sounds like what you're trying to do is to encourage the fuel (the flux) to oxidize (burn) using the oxygen in the metallic oxides (reducing those oxides)--before it is completely consumed and getting all of its oxygen from the ambient air.

I've done this before (unintentionally, not having any idea what I was doing), but the oxide layer--while beautiful to behold in its colorful splendor--was extremely thin. This will be a fun experiment for the weekend. Thanks.

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delmarskid1 posted this 03 April 2015

If you can get your hands on a little tumble lube I would try to shoot them as cast. cylinder throats and rifle barrel leades do a wonderful job of sizing bullets.

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R. Dupraz posted this 03 April 2015

First thing first. If that bullet isn't big enough to fit the cylinder throats, everything else is wasted effort.    delmarskid1's advice is right on . That's exactly what I do for my Ruger NMB 44 special. The RCBS 246 grn PB from WW's drop the same size as the throats. With Liquid Alox, no sizing and either SR 4756 or Unique, the pistol shoots right fine groups with no leading.

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Bongo Boy posted this 03 April 2015

Yup...nothing like a 20 ton press built right in that doesn't even take up any bench space. It's hard for me to imagine the bullet isn't the size of the cylinder throat by the time it gets there, regardless of what size it is in the case mouth...but, mysteries abound and I'm busy working on that die to see if it can't be salvaged. Those RCBS sizing dies must be some decent tool steel hardened to the hilt. I'd just like to see if I can't go this way first, as I'd like to avoid yet another process just for revolver bullets. I'd actually rather sell the revolver and get a Desert Eagle...but it's a bit early for such a rash move and swapping out one set of challenges for another. :)

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delmarskid1 posted this 04 April 2015

When I have felt the need to open up a sizing die I have heated said up to a nice bright red and let it cool off of it's own accord to soften it up. They polish out nice then. I haven't re-hardened one yet. Maybe it's needed maybe not. I hope that I live long enough to find out.

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R. Dupraz posted this 04 April 2015

I don't know about the RCBS dies but  Saeco sizing dies come with a fitted “push pin. I would imagine that RCBS does the same thing. If they can be marked with a file, they can be lapped.         However given the figures that you have posted for the cylinder throats and the sizing die that you have, you are looking at .enlarging the die at least .002” + in order to fit the bullet to the throats. That's a lot. I can tell you from having regularly lapped sizing and loading dies that going that far is not only a lot of work especially by hand but also that you run the risk of lube leakage around the ejector pin if one goes much beyond .001” + when sizing bullets unless an oversized pin is made.        It would seem to me that the logical solution to your problem would be to buy a .431” sizing die. And then if it is a little under size it could be lapped without too much of a problem. I have a Saeco die now that needs to go out about .0003"-.0004'' to make .311". Every new Saeco sizing die that I have bought in last 10-15 yrs. has been under size and needed to be lapped larger to meet it's specs. Not like it used to be.  

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onondaga posted this 04 April 2015

Lee only charges $7 more for a custom diameter bullet sizing die in their Lube and Size kits.

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delmarskid1 posted this 05 April 2015

I do get leakage on the Lyman-H die that I opened up.

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gpidaho posted this 05 April 2015

Just opened up a Lee push through die yesterday, .430 just wasn't what my 444 Marlin Handi rifle wanted. Not knowing an easier way, I just mixed up some valve grinding compound with toothpaste and smeared up five of the .430 bullets and pushed them through a few passes, checked progress and repeated. It only took a couple dozen painted slugs to open the die up to .432. Wrapped a 410 shotgun brush with brass wool and chucked it in a drill motor to finish up. Now to see if it works better at .432. Great thing about working on Lee stuff, if you monkey it up your not out a lot of money. GP

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onondaga posted this 05 April 2015

http://www.castbulletassoc.org/view_user.php?id=8045>gpidaho

One of my ultra modern high teck tools for enlarging Lee bullet sizing dies. This is a Cottonwood twig from the yard, some 300 grit emery cloth in a slot in the twig and I add a little oil before spinning with an electric hand drill .

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Brodie posted this 05 April 2015

Gary, That looks a lot like some  of the expensive, hi tech, rare tools that I own. Brodie

B.E.Brickey

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Pigslayer posted this 07 April 2015

Bongo, What is your groove diameter vs. your throat diameter? Pat

If someone else had of done to me what I did to myself . . . I'd have killed him. Humility is an asset. Heh - heh.

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Bongo Boy posted this 17 April 2015

R. Dupraz wrote: ...given the figures that you have posted for the cylinder throats and the sizing die that you have, you are looking at .enlarging the die at least .002” + in order to fit the bullet to the throats. That's a lot. I can tell you from having regularly lapped sizing and loading dies that going that far is not only a lot of work especially by hand but also that you run the risk of lube leakage around the ejector pin  Yes, and that's exactly what happened. It's possible, I suppose, that RCBS dies are case hardened--because it seemed I had to spend a LOT of time getting it to move the first 0.001", and then suddenly it was another 0.002". I think I actually opened it up about 0.003", and now of course it's just an o-ring retainer in the parts drawer. It's also possible, and more likely, I just frustrated and spun that sander 10 minutes longer than I should have. :) Oh well, definitely not the most expensive mistake I've ever made. As for groove diameter, no, I have not yet measured that. The revolver is getting a .431 sizing die to cater to its needs, and that's the end of it. Given I fired an 18 round 1.5” group offhand at 15 yds using the other 240 grain bullets, the same lube and same die, I'm definitely not fussing with this any more other than to bracket the loads a bit to see if there's a sweet spot. If I can't get the Keith bullets to tighten up through a better load, I'll just not cast those bullets again--I've got no attraction to them really although they come in at a nice weight. But I punch paper...penetration isn't really that big a concern.

Shame on me for even worrying these bullets in the first place--I wasn't solving any problem I had, and in fact just added a problem I don't have much interest in solving. I've got 16 lbs of 4227 on the way--I'm sure I can find a plinking load that will provide hours of enjoyable blasting.

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S.B. posted this 26 November 2016

Who cut your mold? I have both a 260 and a 310 Keith from LBT and both work great! Steve

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