38 special loads - case bulging

R.M. Conversion · January 13, 2019, 02:00:54 PM

I recently made up a batch of .38 special BP loads, and they all came out fine, except for the ones with PMC cases. I've never had a problem with PMC in smokeless loads, but sure enough, they wouldn't chamber with some (not terribly) compressed BP loads. They'll go to the scrap bin now.

Abilene · January 13, 2019, 02:59:09 PM

I have never had a problem with PMC in any straight-wall caliber. Where is the bulge?

hellgate · January 13, 2019, 03:42:32 PM

Get a carbide 38/357 factory sizer/crimp die from LEE. You run all finished cartridges through it (like a sizing die) and it makes sure they will chamber. You can set it to not crimp at all if you want. Some brass is too thin and may bulge or too thick and the bullet+thick case wall won't let them chamber. Also tight chambers will prevent all but the smallest cartridges to chamber. I run all my loaded .357 ammo through the die and do not have chambering problems like before.

Too much powder and a thin case wall or too thick of a case wall is the problem with the PMC hulls. Try less powder. If not better try a smaller diameter bullet (.357 instead of .358)

I found WW nickeled cases wouldn't chamber with a .358 dia bullet in one of my Rugers but had no problems with RP Nickeled cases which were thinner.

Dick Dastardly · January 13, 2019, 10:55:02 PM

Not all brass of the same caliber has the same internal volume. Take some proprietary brass and weigh the water volume. You may find that your PMC brass has a smaller internal volume. If that's the case you may need to back off your powder charge a bit to avoid case bulging. BTW, PMC brass is good brass, just different.

DD-MDA

Coffinmaker · January 14, 2019, 10:20:11 AM

PLUS ONE to ALL those other guys ABOVE.

or

WHAT THEY ^ SAID

R.M. Conversion · January 15, 2019, 07:30:02 AM

The bulge turns out right around the projectile. It was odd, out of about 400 of them, they were the only ones affected. I noticed it while I was loading them, too. StarL, R-P, Win, USGI, CCI - all the others were okay.

R.M. Conversion · January 15, 2019, 08:37:46 AM

Also, I've always been hesitant to run a primed, charged case through any sort of sizing die. Besides, that may cause problems with sizing the bullet smaller. Better to continue to use a case gauge to insure proper chambering - or just sort out the PMCs from the git-go.

Charge used is 17g of 2F.

Abilene · January 15, 2019, 10:19:59 AM

Well if PMC brass is too thick, then you should also cull out any CCW or CBC headstamped brass if you pick up any, as it is even thicker.

edit: I meant WCC, not CCW.

hellgate · January 15, 2019, 11:09:34 AM

It is a different caliber but CBC nickled in .357 mag is one of the thinnest like RP. CBC .223 Rem is very thick so case wall thickness varies for each caliber within the same maker. To measure case wall thickness take a jacketed bullet, mike it then seat it and measure the total thickness. .357 case walls vary by about a thou.