Shrinking sizing die.

[Thompsoncustom]

Well the other day I went out shooting and was really having a hard time hitting the paper with my glock 17 so with a couple rounds left I pulled out the CZ 75b and put one in the bulleyes and thought it must have just been the gun except that I didn't hit the paper again till I walked up right next to it and fired 2 into it.

Problem was my bullets were undersized but the reason this is crazy to me is I have opened my sizer up to .3565 and my barrel slugs at .3555 well long story short I grab a bullet and sized it and it came out at .3555

So how does a sizer shrink? All I can think is maybe it got some rust in there and the boolits polished it down a little. Opened the sizer back up to .3565 the same way I did before so leading should stop it just puzzles me.

The undersized bullets are lee 125gr RN think I came put enough pressure behind them to bump them up? I have 200 left coated with the hi tek coating.

[btroj]

Not all alloys size down the same. How do you know what your sizer dimensions?
A softer alloy can come out of a sizer smaller than a higher Sb alloy.
Don't depend on bumping them up to improve accuracy. If they are that much too small then they are way to small. Melt em down and start over.

[ku4hx]

Not all alloys size down the same. How do you know what your sizer dimensions?
A softer alloy can come out of a sizer smaller than a higher Sb alloy.
Don't depend on bumping them up to improve accuracy. If they are that much too small then they are way to small. Melt em down and start over.

This. Even if you could "bump them up", there's little assurance you'd be consistent in the amount of force you applied and resultant boolit size would vary still.

I hate to think of the number of lubed and sized boolits I've remelted over the years. Just one of life's little joys and part of the nature of the hobby.

[theperfessor]

Could there have been a buildup of liquid Alox or other crud in your die? You didn't mention when you apply lube, but many folks lube, size, and lube again.

[nhrifle]

Search the forum for posts relating to using a .38 expander instead of the 9mm expander. Sounds like you are having the same problem I had, the case reducing the size of the boolit when seating. The cases need to be expanded more when seating lead than jacketed and when I switched to a .38 expander my problems went away.

[462]

Your sizing die didn't shrink. Your expanding die and/or seating die are the culprits. And, if you use a Lee carbide factory crimp die, it has an infamous reputation for putting the squeeze on boolits.

[texassako]

The 2 ways I can think of it 'shrinking' is lead, LLA, the hi tek coating, etc. building up in it, as theperfessor says. The other way could be spring back. I assume you run them through coated? Did you open it up originally using regular lead boolits to check for size or these coated bullets? I would think it would cause the opposite(to big), but maybe the coating helps it slide through or prevents the boolit from springing back as much.

[Firebricker]

Need more details but if your using the Lee fcd that is probably it. The fcd works great but is designed to be used with .355 boolits. FB

[Thompsoncustom]

More info.

Lead bullets and coated bullets came out the same as that is how I check my sizing die. Nope nothing was inside the die as I cleaned it and even used the method of 50/50 hydrogen/vinegar to make sure there wasn't a lead build up of some sort.

Expander or case sizing didn't cross my mind because i'm just talking about the bullets not completed rounds. Last time I checked the bullets after they had been forced through the die they were .3565 and the other day they came out .355 I have two pairs of calipers to make sure ones not geeking out.

could be alloy but my alloy has always been the same straight wheel weights so I don't really know what it all is made up of.

FCD! haven't used that thing is years, Ive been there and done that and I'm not going back. Also don't use alox but pan lubed before this new coating.

[Case Stuffer]

I have two pairs of calipers to make sure ones not geeking out.


Calipers are not as accurate as Mics.,never have been ,never will be.

[Thompsoncustom]

Expander could be the problem that's causing leading in the barrel as I turned it down some the other day so I just went and seated a lead/lube bullet and pulled in and it's not being sized down but I don't have any coated bullets that aren't undersized to check.

[popper]

Bump up a few coated ones with a hammer on the base, size and measure. Don't know what your alloy is but you HT them with the air cooling. Add some more HiTek coating to build them up a bit. I use a chore boy to clean my sizer. I don't size before coating.

[462]

Oops, missed the part where you said measurements were taken right after sizing. I was thinking you measured a pulled boolit.

[Firebricker]

Oops, missed the part where you said measurements were taken right after sizing. I was thinking you measured a pulled boolit.
I did too. FB

[Thompsoncustom]

Used a hammer to bump the coated bullets out to .3560ish and than ran them through the sizer. Loaded them as a normally would minus the primer and powder than pulled them and just like the lead they do need appear to be squeezing the bullets down any.

So the problem seems to solely be the sizer from what I can tell and it magical went down some but like I said I opened it back up just would have never imaged it shrinking and still don't but nothing else seems to be the culprit from what I can tell. I guess the real test will be when I melt these bullets down and load some new ones up.

[MtGun44]

.3555 with a caliper means somwhere between .3545 and .3565. Can't
really do this work without a .0001" mic.

Bill

[popper]

hammer on the base, size and measure So what did they measure, after sizing? For 200, I'd coat again, WD, wait a week, size & measure. If the cooking HT softens them, they won't spring back to the sizer's indicated size. After WD & hardening, they may grow + spring back to the proper size. If you keep enlarging the sizer you may end up with one that sizes too large to chamber. SIZERS DON"T SHRINK. Then you get to buy a new one like I did.
Lead bullets and coated bullets came out the same That would be normal. New batch of WW? They aren't what they used to be. If the alloy really is softer, they won't shoot good no matter what coating.

[Thompsoncustom]

Leads all the same since I started casting got free wheel weight from a friend at a tire shop and i'm almost out so what's been in the pot has been into there for a while. They measured .3565 what I opened the sizer back up to.

I guess I just don't know what else to balm. When I got the sizer new it sized bullets to .355 so I opened it up to .3565 and haven't had any problems with it since. Than the other day it to pushing them out at .3555 and I was getting leading like a sewer pipe but i've opened it back up and I'll do some more casting and see what happens.

[fredj338]

Casting temp can change final dia. your die isn't shrinking, likely the bullets are & not really getting any sizing form the die. WW alloy also varies form older to newer.

[MT Chambers]

Lee dies, Lee molds, Lee sizing die, your odds aren't good.

[Thompsoncustom]

Lee dies, Lee molds, Lee sizing die, your odds aren't good.

Lol I have a lyman mold I use to. But ya I have a lot of lee stuff tho when I can find a new hornady lnl press in stock that's not crazy priced I'll be upgrading using a lee hand press right now...

[williamwaco]

Your sizing die didn't shrink. Your expanding die and/or seating die are the culprits. And, if you use a Lee carbide factory crimp die, it has an infamous reputation for putting the squeeze on boolits.


Ditto.

I have seen this many times
It is usually caused by an expander that is too small.
It is especially common with 9mm.

I have never used the Lee FCD. I have heard so many complaints about it I never tried it.



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