Oversize bullets from mold

B

back40sniper

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Any way to change lead mixture to reduce size of dropped bullets? Change in heat of melt or mold? My 9m mold is consistently dropping a few thousands large for what I what to do. I have not had any problems with casting 45/70, 416 Rigby, 41 Mag or 375 H&H with alloy I use but this 9mm mold is different. Hope to not have to buy another mold.
 
Buy a cheap sizer. They'll all be sized to perfection, and it doesn't cost a lot. The Lee push-through dies work well.
 
I had an RCBS mould in 9 mm. that threw its bullets .359 inches. With my hard alloy and powder coating, it was .361.
Too hard to resize down to .356 or .357.
I sold it and bought an Accurate mould that casts perfect bullets.
They have a design for powder coating that is a whisker smaller at the throat, where the sizing die won't touch, to make up for the p/c thickness.
 
I have found that with most of my molds and my desire to PC everything, nearly all my bullets are too big. There doesn't seem to be an effective option outside buying different molds. Running my pot colder and different alloys were suggested but nothing made a noticeable difference.
 
B said:
I have found that with most of my molds and my desire to PC everything, nearly all my bullets are too big. There doesn't seem to be an effective option outside buying different molds. Running my pot colder and different alloys were suggested but nothing made a noticeable difference.
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Why not size after PC?
 
Quigly said:
I can't speak to your situation but, I size after powder coating and the bullets are exact diameter.
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What sizer do you have that works over the entire profile of the bullet? Adding PC means jamming the bullet into the rifling if I can't seat it deep enough, which I often can't without running into feeding or pressure issues.

This isn't a problem with all my molds but it is with many. I wish I had realized before I bought two dozen molds on a whim. I tried some of the stuff mentioned by the OP. None seemed to work unfortunately.
 
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If nose protrusion is a problem and seating them deeper isn't possible then running them through a sizer won't help with that, obviously. I've run into this problem too and all I could do was cut some material back which is not too practical.
 
Pure lead will drop the smallest diameter, followed by Wheelweight, Lyman #2 and Linotype, which can increase diameter by about 0.5% over pure lead (about 0.002" over 0.457"). The same progression sees weight drop and hardness increase.
 
I cast my bullets, size them all to .356" so they are a consistent diameter, PC them and then resize again to .357". It's a little bit labour intensive but PC'ing them when they are all the same diameter makes them easier to size the second time around. These are the Lee 125 gr. 2R bullets which have a bit of a large ogive so I do have to seat them a little deeper than with some other styles (usually about 1.10").
 
Thanks all, my bullets drop about 357 ish, I resize to 356 and powder coat, then have to resize to 357/358 but it takes some of the powder coat off. And, I have to "lean" into the sizer to do it. My powder coat stands up to the smack test perfectly . I never had to put this much effort into resizing my big calibers, or do it twice.

Going to have to bite the bullet, see what I did there?, and just get another mold. Sucks, because this mold is from a good mold maker and is supposed to be for powder coating.
 
back40sniper said:
...then have to resize to 357/358 but it takes some of the powder coat off. And, I have to "lean" into the sizer to do it.
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I find this unusual. I have PC'd and sized literally thousands of bullets using this technique and have never had any powder coat removed. in fact most of the time the bullets come out unmarked so you can't even tell they have been sized. What type of PC are you using?

Also, I'm surprised it takes that much effort to resize. Since you are pre-sizing to .356 and PC'ing usually only adds about 3-4 thou that gets you up to around .359-.360. But if you're only resizing down to .357-.358 you are only talking 1-3 thou reduction which is really minimal. What type of press are you using (I'm using a Rockchucker).
 
back40sniper said:
Any way to change lead mixture to reduce size of dropped bullets? Change in heat of melt or mold? My 9m mold is consistently dropping a few thousands large for what I what to do. I have not had any problems with casting 45/70, 416 Rigby, 41 Mag or 375 H&H with alloy I use but this 9mm mold is different. Hope to not have to buy another mold.
Click to expand...

Everything you should know about casting..alloy shrinkage.. more lead alloy (read soft) = larger bullet..
http://www.lasc.us/castbulletnotes.htm
 
Alloy casts to about a 12-13 BHN so it should be in the ball park for handgun, can't remember brand of PC but it works well. Squash test on a 9mm bullet, bullet looks like a quarter and powder coating won't come off.
I am using a Lee APP press to resize, haven't tried it on my Redding Big Boss and used to also use a Lee single press . going to try going harder/softer on alloy just because I am stubborn.
 
back40sniper said:
Alloy casts to about a 12-13 BHN so it should be in the ball park for handgun, can't remember brand of PC but it works well. Squash test on a 9mm bullet, bullet looks like a quarter and powder coating won't come off.
I am using a Lee APP press to resize, haven't tried it on my Redding Big Boss and used to also use a Lee single press . going to try going harder/softer on alloy just because I am stubborn.
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While the Lee APP is a great little unit for some jobs (in fact I have one) it is a little flimsy for bullet resizing. Put your sizing die in the Big Boss and you'll barely notice any resistance at all when resizing.
 
back40sniper said:
Thanks all, my bullets drop about 357 ish, I resize to 356 and powder coat, then have to resize to 357/358 but it takes some of the powder coat off. And, I have to "lean" into the sizer to do it. My powder coat stands up to the smack test perfectly . I never had to put this much effort into resizing my big calibers, or do it twice.

Going to have to bite the bullet, see what I did there?, and just get another mold. Sucks, because this mold is from a good mold maker and is supposed to be for powder coating.
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Try spraying the bullets with a spray-on case lube like the RCBS Case Lube 2 or Frankford Arsenal and run them through the sizer. Should work fine. Had the same problem with our powder-coated 142 grain Saeco #383 SWC bullets. Just a little spray lube fixed it. It doesn't seem to deactivate or affect the powder.
 
I have an Arsenal mould for the .45 Colt that was producing slightly oversized bullets (.457 dia) and I knew there had to be something stuck on the face of one of the mould blocks because the first few hundred I cast had come out at .453 dia. Carefully examining the blocks I found the smallest sliver of melt in the center-rear-end of one of the blocks that I removed with a piece of wood. Everything is fine now but it drove me slightly nuts trying to find it.
 
calmex said:
Try spraying the bullets with a spray-on case lube like the RCBS Case Lube 2 or Frankford Arsenal and run them through the sizer. Should work fine. Had the same problem with our powder-coated 142 grain Saeco #383 SWC bullets. Just a little spray lube fixed it. It doesn't seem to deactivate or affect the powder.
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I was going too recommend this. I spray a quick shot of Lyman case lube on 50 ish coated boolits in a plastic tub. swirl and alternate between lubed and non lubed It's super easy even with the big 360 grain 45"s.
 
Tried sizing in BigBoss press and is easier but still some resistance to it, have lubed bullets and it helps but I think this mold is just starting bullets out to big to start with for what I want. Will check mold sides for interference, there might be something to this as some bullets seem to be out of round. This is from a batch that I was very careful to put steady pressure on mold handles. I usually use a pair of handles that over center and lock closed.
Will still try changing alloy mix as had a couple bullets had metal smeared along the bottom edge. Too hard, too much tin, maybe some babbit metal left in melt from making a "serious" bullet for DG project?

Thanks for all the help, I have never had this much trouble casting bullets before.
 
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