Where has this brass been?

[DesmoDucRob]

I've been coming across some 9mm brass that has a significant bulge near the headstamp. I know a vast number of people are ready to yell "Glock belly" or "Glock bulge" but I'm shooting a Glock, and when compared to my spent rounds, these cases are noticeably more bulged. I'll attach some images of my "Sharpie contact test" that I use to diagnose problems on rounds that will not chamber. The loaded cartridge measures .393" at the point where the wear mark is. It's easy to identify these rounds from the rest, by using my barrel as a case gauge; the rounds are nearly 1/4 inch from fully chambering- nowhere near full battery.

I've also noticed that on some of the cases with this problem, there is a dented area near the rim. What kind of 9mm bulges cases so significantly near the headstamp?

 

[Texasflyboy]

What kind of 9mm bulges cases so significantly near the headstamp?

Subgun. Likely suspect is a MAC or an UZI. The bent rim is the bolt slamming into the stationary round sitting next in line in the mag. I think the MAC has an agressive angle on the round sitting next in line in the mag.

Regarding the bulged base. Have you checked your die to ensure than it has less than .005" clearance between the base of the die and the shell holder?

The only other suspect I can tell you is that yes, carbide dies do wear out. It takes tens of thousands of rounds to do it, but you can wear out a carbine resizing ring. Try a new sizing die and see if your sizing problem goes away.

 

[tactical723]

Do you get the bulge with every piece of brass, this would rule out the die problem, try a different lot of brass, also are these military crimped 9mm shells with the NATO stamps, I just rec'd some of these for the first time and have run into nothing but problems going through my carbide dies. It is very obvious as Texas concluded that these were fired in a subgun, if the gun was fired off time, the case would bulge and if you are not full length sizing, then the die is not re-sizing down into the bulge section, this would continue to be a problem

 

[DesmoDucRob]

I didn't consider a subgun, but that is likely. The brass is once fired, that supposedly came from a test center (2nd hand info.) that included Uzis among other firearms. The problem is not with all brass, but most of the pieces that have the bolt mark on the rim are bulged. My dies (RCBS carbide) work fine with cases that were fired from the more common pistols so I'm ruling the dies as the source of the problem. Thanks guys, at least you've shined a little light on my situation that suggests this is not a result of poor reloading practices on my part.

 

[scooterj]

If you were picking the cases up at IPSC matches, I'd say they could be from a few of the guys shooting "major 9". Neither of my XD's like those cases.

 

[DesmoDucRob]

If you were picking the cases up at IPSC matches, I'd say they could be from a few of the guys shooting "major 9". Neither of my XD's like those cases.

I considered this, but even "9 Major" would be limited to the size of the chamber of the pistol in which they were fired, right? What pistols are popular for 9-major?

 

[scooterj]

Mostly 1911's and 2011's The pressures are very high and if these guns aren't timed just right, they start to come out of battery before the bullet leaves the barrel. Therefore bulged cases.

 

[Storm52]

You might try a EGW Undersize die. It is a full length sizer and takes the glock bulge out. It may suit your case issue, although not certain. There is a another full lenght die that sizes the entire case by shoving the entire brass up through the die.

 

[DesmoDucRob]

You might try a EGW Undersize die. It is a full length sizer and takes the glock bulge out. It may suit your case issue, although not certain. There is a another full lenght die that sizes the entire case by shoving the entire brass up through the die.

I like the EGW die concept:
http://egw-guns.com/store/index.php..._id=40&zenid=3fd47ff3bae214735e9e51df71d58af7
Does anyone else make a die that sizes further down on the case body (without pushing the entire case through)? I think simply sizing more case wall towards the case head would fix my problem, and that the extra .001 diameter less may not be needed.