9mm Brass Bulge

[DHC]

Would appreciate some input from those of you who load for 9mm on a progressive.

Here is what recently occurred:

Threw some previously fired brass into the case feeder and began running my 'normal' loads. Finished up a batch of about 500 or so and then dropped them into a Wilson cartridge case gauge as a final check. Out of 500, I found maybe 5% that has developed a large enough bulge that they would not 'thunk' into the gauge and some that would not fit at all. I am working from the assumption that if the finished cartridge will not 'chamber' in the Wilson gauge, then it could be problematic later, when it REALLY counts. What I noticed was on the problem cases, most had developed a bulge at the bottom of the case preventing it from fully 'chambering' in the Wilson gauge. The result is I pulled the out-of-tolerance bullets to re-use the bullets and powder, and I am hoping to de-cap the primers intact for re-use as well (shall see how that turns out).

This led me to a close inspection of all the remaining empty cases, but without running them through the sizer, they offer no indication of any problems and I believe the case bulge will not appear until the case is sized. So the problem becomes that it is nearly impossible to determine which of the previously fired cases will develop a bulge that will render the cartridge unusable until after the case is fully loaded.

This is the first time I've encountered the case bulge becoming large enough that is interfered with chambering, though I've read it is not uncommon with 9mm.

Does anyone have any tips/tricks for either identifying problem brass BEFORE starting the loading process? Obviously, any apparent defects are culled out, but how do you detect the possibility/likelihood that a bulge will develop when sized?

Has anyone ever tried a roll-sizer like the CasePro? I've seen a push-thru die for .40 S&W caliber, but due to the taper of the 9mm cases, I do not think anyone offers an effective push-thru die, leaving the only possible option as a roll-sizer to address the bulging problem.

[dwalker460]

The dies is likely not adjusted properly. Make sure that when you are sizing the case the shellholder touches the base of the die.

[DHC]

The dies is likely not adjusted properly. Make sure that when you are sizing the case the shellholder touches the base of the die.

I'll check again. Is it your experience that when properly adjusted the 9mm die manages to eliminate all case bulge?

[cysoto]

Is it your experience that when properly adjusted the 9mm die manages to eliminate all case bulge?

This may depend on the brand of dies that you are using. Some brands of dies have a larger flare in the opening than others. In my case, I had some issues with Dillon dies some years ago which only went away when I switched the Dillon crimp die for a Lee FCD (though be aware that the FCD die is not recommended to be used with bare lead bullets and, in some cases, plated projectiles).

Nonetheless, did you try using your pistol's barrel as a case gauge? Many times case gauges can be somewhat undersized. If they "thunk" in the barrel, you shouldn't have any issues using them in a match.

[DHC]

This may depend on the brand of dies that you are using. Some brands of dies have a larger flare in the opening than others. In my case, I had some issues with Dillon dies some years ago which only went away when I switched the Dillon crimp die for a Lee FCD (though be aware that the FCD die is not recommended to be used with bare lead bullets and, in some cases, plated projectiles).

Nonetheless, did you try using your pistol's barrel as a case gauge? Many times case gauges can be somewhat undersized. If they "thunk" in the barrel, you shouldn't have any issues using them in a match.

Am using a Hornady L-N-L progressive with a Hornady de-capping/sizing die in station 1. Station 5 carries the Lee FCD with Station 4 being the bullet seater. I'm not using bare lead bullets - only jacketed or plated.

No, I didn't use the barrel as a gauge - in part because I am loading for several different 9mm handguns. The cartridge gauge was, I thought, the best indicator of assurance the rounds will function properly in all the handguns.

Interesting point about the FCD . . . Since the bottom part of the case is unsupported when running it up through the FCD, I wonder if that might be the cause of (or contributor to) case bulging?

[gnihcraes]

I check the brass on the wilson before hand. Pain in the butt I know, but it solves all my problems. Singlestage/RCBS dies, max full length size, bulge still exists.

Some particular gun(s) out there have a loose chamber and are bulging. Maybe some particular machine gun? I believe the brass I have trouble with are .mil cases.

[DHC]

I check the brass on the wilson before hand. Pain in the butt I know, but it solves all my problems. Singlestage/RCBS dies, max full length size, bulge still exists.

Some particular gun(s) out there have a loose chamber and are bulging. Maybe some particular machine gun? I believe the brass I have trouble with are .mil cases.

I am surprised your previously fired brass will fit the Wilson gauge before sizing. Most of mine will not.

[cysoto]

Interesting point about the FCD . . . Since the bottom part of the case is unsupported when running it up through the FCD, I wonder if that might be the cause of (or contributor to) case bulging?

Is your FCD "kissing" the shell plate?

[DHC]

Is your FCD "kissing" the shell plate?

I am going to check the adjustments on all dies and report back. I *think* they are correct, but it can't hurt to check again.

[gnihcraes]

I am surprised your previously fired brass will fit the Wilson gauge before sizing. Most of mine will not.

** Clarification, after sizing. Most slide right in and out.

I use an old pencil on the workbench top, holding the case gage over it, then press each brass down in the gage, the pencil allows me to eject the brass quickly. (no tapping or shaking) If the brass doesn't fit easily, I set it aside.

I usually end up with a handful of bad brass, I pitch it in my recycle bucket for the scrapyard.