Dirty 9mm Brass

[Hanzy4200]

Possibly check your brass quality, and there is the good chance your chamber may be oversized. Is it a bargain bin upper? I've seen some pretty rough chambers in the cheaper gun show upper.

[Hanzy4200]

I settled on a .358 powder die. My barrels all slug @ .356 (+/- .0005), so I think at .358 I definitely get enough squeeze to seal the chamber. Crappy part is now I have to melt down all the bullets I sized to .357 and start over.

Unless your REALLY need the alloy, or if it's a large amount, you might want to just hang on to them. 9MMs vary widely in bore diameter. You might get another 9 in the future that likes .357's.

[Pbaker]

I have approximately 1,000+ rounds that I sized to .357. It would be easier to just scrap them and melt them down with a batch of COWW. It’s much easier to size everything to .358 for now, and then size again to .356-.357 when/if needed.

My upper is an Aero, as well as the barrel. From my measurements/estimate, the throats will accept anything smaller than .3605”. So sizing to .358 should work out just fine.

[David2011]

I have to disagree that 9mm doesn’t need a crimp. It should be taper crimped to 9.65mm/0.3799” at the mouth. I measure “a hair’s breadth” behind the mouth to be sure I’m not measuring on a burr. The taper crimp assures adequate case tension.

[AlHunt]

I have to disagree that 9mm doesn’t need a crimp. It should be taper crimped to 9.65mm/0.3799” at the mouth. I measure “a hair’s breadth” behind the mouth to be sure I’m not measuring on a burr. The taper crimp assures adequate case tension.

And gives you a better chance of consistency. Not that the short distances people seem to shoot 9mm at require match grade ammo but I like to crimp.

[Pbaker]

On a side note/issue, has anyone tried to custom fit their seating stem using JB Weld? I’m getting the olé smiley face on the tip of my RN bullets. Thinking about re-profiling it with some JB Weld

[bangerjim]

Faster powders are your solution.

Dark brass.....no problem. Dirty brass (with rough crud on it) needs to be cleaned but shiny new IS NOT required for any load!

[Pbaker]

The reason I settled on HS6 is because I’m using an 8.3” barrel, so I figured the slower burn would be good for this setup. Many people use HS6 for many pistol applications, so it’s not particularly a powder issue. I definitely have/had undersized bullets, possibly mixed with a light load. I need to mix up some more loads with larger bullets and see where that gets me.