Poll: Need Help With the Fun Gun - Cobray M-11

[badbob85037]

Back about 94 I bought me a fun gun, a Cobray M-11. I have repaired it many of time and I will buy a replacement barrel and until I do I'll use the 10" barrel I have had for a few years. You own one of these and when you see parts at the gun show you buy them. What I want to know is why it happened I reload the 9 mm for it but I use a Dillon press so the chance of a double charge is near impossible. After the round fired the ejector picked it up and brought it back about half way and stopped at the time I thought the ejector broke and wedged between the frame and the bolt

When I got home i got the shell out. What was holding the bolt was the barrel as if the barrel was bent down. Not enough to notice it with the eye but enough to matter. The spent case is shaped a little like a hour glass but not to that extreme The two bulges are both .400. The primmer, what's left of it is flat as a pancake with a hole in it's center you can see light through . What do you think happened? Now that I put the two barrels side by side the barrel also looks as if it is also is bulged. Maybe there was a round in the barrel when the other one was trying to go down it? The longer I look at this case the luckier I feel

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[thorborg]

The only Cobray I've touched (but not shot) was a M11 but a 380. I was less than impressed for a variety of reasons with the overall lockup integrity on the loose side though without a cartridge in it.
I could see how forcing a round into battery with an obstruction could cause an hourglass case however I'm not feeling good about it being a squib since I believe the results of a second round slamming a squib in that particular device would provide you more excitement than just a lock up albeit I'm no expert.
The fact that your primer was not ejected from the case but was flattened with a hole in it seems to indicate a lock up but with a pierced primer. For that issue alone, I would check the firing pin length and shape. If the firing pin is of proper shape and length it may be because the primer was not seated to proper depth during loading.
Weather the pierced primer is a cause for your other woes or a side effect of something more sinister I cannot tell from info on hand. I would be disinclined to shoot it again, even with a new barrel, without an explanation and correction.

 

[nvshooter]

Only experience I have with Cobray firearms is with a suppressed, full-auto MAC-10 in .45ACP; that was in March 1984. Tons of fun but holy-moley, are they expensive to feed!

 

[RobErvin]

Full auto is fun but it's really a huge waste of ammo. I recall watching a demonstration on Youtube from Hickok 45, where he showed how inaccurate full auto fire can be. They don't call it spray and pray for nothing.

Edit: I found the video.

 

[nvshooter]

Full-auto is fun but it's really a huge waste of ammo.

I think full-auto was put into shoulder-fired weapons so as to have an individual soldier with a volume of fire to better keep down the enemy's heads. That's what is the reason for a tripod-mounted machine gun: Suppressing fire to keep the enemy hidden, not firing back and to gain forward ground. Nobody wants to stick his head above the berm and have a hole put through it. Aimed fire is much more effective, but the fact that many bullets are coming in a flood is quite a convincing argument to stay behind your cover.