burning slits in Super cases

[ErikW]

I noticed two of my spent cases this weekend had small splits in them with signs of gas venting. The splits do not start at the case mouth, they are farther back, about where the base of the bullet is. They are about 2mm long. Gas burns at front and back.

W.T.F. ?!?

RP .38 Super +P brass case, loaded new and fired, then loaded again with 115 gr/3N37/WSR for this firing. Nowlin barrel, nothing suspicious visible in the chamber.

Gun ran great all weekend, except for one or two slight hiccups where the slide seemed slow or slightly resisted picking up the round in the mag. (This isn't unusual; I sometimes drag the slide with my thumb.) Never noticed any change in sound or smoke or gas venting.

[EricW]

Erik,

I don't shoot sooper, but I see this a lot with the Open shooters cases at the range.  I'm guessing that it's just a sign of the case bulging right at ignition before the bullet moves.  The super case probably has enough thin sidewall for the case to "balloon" in the chamber.  (If that visual makes any sense...)  I don't think there's really anything to be done about it, short of rebarreling your blaster with a tighter chamber.  

FWIW....

E

[shred]

Yeah, while 'common' is a bad thing, they happen occasionally.  My feeling is that they're probably tiny cracks or defects in the brass that leak gas when fired.

Back in the 9x25 days, I had some Remington nickel 10mm brass would crack 50% of the time on the second firing-- they didn't heat treat or stress-relieve that batch correctly.

[ErikW]

Hmm, Nolan thought the brass wasn't annealed properly. You think I should try re-annealing?

I'm not too excited about shooting 300 rounds of this twice-fired brass at the Infinity Open.

[EricW]

Erik,

My $.02 is to be damn careful if you try annealing the cases.  I know they do this with rifle cases with a torch with the head sitting in a pan of water.  But...with a pistol case being as short as it is, the risk of accidentally annealing too far down seems fairly substantial.  Why not just shoot'em 'till they crack & call it a lesson learned?  The cure could be worse than the disease here.

My 2 pesos...

E

[Patrick Sweeney]

I agree.  Retire that batch to practice, use something else, and throw them out as they crack.

[ErikW]

Dammit, I just eliminated the whole "practice brass" and "match brass" issue with my Soopers. Now I've got to have a "bad" batch and a "good" batch? <moan, bjtch, whine>

[kbear38S]

Remington recently replaced a bad batch of Super nickel for me. The plating was bad and peeling off - in the press, in the gun, in the tumbler and right from new. I'm inclined to think they're going to say your load is over pressure but it would be worth your time to contact them and try to get them to make it right.

[benos]

"I agree.  Retire that batch to practice, use something else, and throw them out as they crack."

Bingo.

be

[Nolan]

Erik,

I don't think there is anything wrong with your barrel or chamber.  I think you've got a bad batch of brass.  I've picked up a lot of your brass and haven't ever seen anything out of the ordinary before.  I had similar problems with one batch of Starline brass in 38 Super.  About 20% split on the first firing.  Scared me when I saw how badly the brass had split.  Much worse than your measley little 2mm.  Some were split half the case length with a few radial cracks as well.  I didn't notice anything different in the way the gun sounded or felt while I was shooting.  

I sent samples of unfired, split and unsplit fired cases back to Starline.  They mumbled something about a batch that was too hard when I talked to them on the phone.  They promised to replace the bad brass, but I never got around to returning it.  Hmmm, there's a project for this week.

Have you changed brands of polish or case lube?

Buy some Wimpchester brass from a different vendor and see if it splits.