Ammo malfunction with MK II

[aomagrat]

I was shooting my MK II today. The first couple of rounds fired OK. The next one went off with the feel of a 9mm. The slide locked back and debris peppered my face. I looked in the chamber and saw that the case was still in the chamber, but the case base was completely gone. The next round in the magazine was bent into a V. The remaining case was easily pushed out with a cleaning rod. The base was not found. I've had cases rupture before but never in my MKII and never seen one with the base blown clean off before. I was shooting Winchester 555 bulk pack.

 

[WIL TERRY]

CASE HEAD blew off any of several reasons. It was chopped off because it was NOT supported by the chamber plus a bit of excessive headspace in all probability. NO BIG DEAL in a 22LR pistol ! IF it's never happened before I'd bet the north 186,000 acres it was an ammunition problem. Shoot the rest of 'em up in your 22 revolver.
I used to have a foreign 22 pistol that cut the rim off CCI MINIMAGS with amazing regularity. ONLY CCI's !
And so it goes...

 

[Rocdoc]

I've had the same thing happen with a Stevens favorite that was produced in the last few years, not one of the old ones. I was hoping it was the cheap bulk ammo I was using, but have been reluctant to shoot since this happened the last time. Savage had no interest in looking at the gun unless I paid them to do so.

 

[Mobuck]

Out of battery ignition would be my guess. Is your extractor OK?

 

[aomagrat]

Out of battery ignition would be my guess. Is your extractor OK?

The extractor is fine. I fired about 40 rounds after the incident with no problem.

 

[hboswell]

I have only ever had one case split at the base like that, it was in a Walther P22, and the only damage was a broken slide lock spring. That too was Winchester 555 and I no longer buy it, too many light loads and ignition failures.