Thread: Odd primer strike

Figure some of you guys know exactly what is going on here:

New to me, would not have to be forensics investigator to recognize this casing!

It looks like this round was not fired in a firearm chambered for 9mm Luger. Can you provide more details? What do you want to accomplish with this thread?

It looks like the firing pin hole in the breech face might be oversized, which would cause the primer bulging. On the other hand, it almost looks like the wrong primer. The top surface doesn't come anywhere near the edges of the primer pocket. Do they all look like that?


elsie

Did you shoot a 9mm in your .40 S&W?

Originally Posted by civilian75

It looks like this round was not fired in a firearm chambered for 9mm Luger. Can you provide more details? What do you want to accomplish with this thread?

The gun is a 9mm Stoeger Cougar which shoots just fine. I only noticed this at the range compared to other hulls. The
ammunition is new remington. All of them look alike from this weapon. Don't expect to accomplish much by this thread;
solve a curious case, give folks something to chew on, talk to fellow forum members.

Originally Posted by nubus

Did you shoot a 9mm in your .40 S&W?

I don't own a .40 otherwise I may do something like that without proper supervision

Originally Posted by elsie

It looks like the firing pin hole in the breech face might be oversized, which would cause the primer bulging. On the other hand, it almost looks like the wrong primer. The top surface doesn't come anywhere near the edges of the primer pocket. Do they all look like that?


elsie

I will take a look at that, they all look alike. Looks like some "leakage"? browning the case on one side too.
my old P-38 does not do this. I think the primer looks that way because of the photo

I think the chamber is a bit too large for 9mm. Notice how the primer strike is off centered, and the breech face extruded into the rim of the primer pocket, with a crescent moon shape. They all look like over-pressure signs I've never seen on factory 9x19. The case browning is uneven as well, showing only on the side where both the primer strike and crescent moon are. All these signs lead me to think it was not fired on a 9mm Luger chambered gun, but maybe something like a 9x18 Makarov. Since both 9x19 and 9x18 headspace at the mouth and must be tapered crimped if at all, a 9x19 in a 9x18 (which is .363", not .355") could have created higher chamber pressure if the 9x19 case got in too deep.

The only two other possible explanation I can think of is it was not on battery when the primer was stricken, but that does not quite explain the over-pressure signs, or, Remington loaded it too hot by mistake, but that does not explain why the strike is off centered.

Possibly depth of primer??? Don't know just guessing.

Elsie is right the hole in breach face is to big causes the primer to flow back into hole....I have had a couple of these issues sometimes you can change ammo and it will fix problem. Allmost all master piece arms do this and they say not to worry that is how their guns work..lol

I think one of two possible problems. Since the 9mm case headspaces on the case mouth I would check the case length 1st. It may be too short causing the case to launch back when fired. The second possible answer the barrel may be flawed allowing the case to seat too deep. The case slams back on the breech during extraction causing the weird mark on the case. Send the gun back to Stoeger if this happens with different bullet brands.

One thing is certain - it ain't right. I'd get with the manufacturer for sure.

Originally Posted by mobil890

I think one of two possible problems. Since the 9mm case headspaces on the case mouth I would check the case length 1st. It may be too short causing the case to launch back when fired. The second possible answer the barrel may be flawed allowing the case to seat too deep. The case slams back on the breech during extraction causing the weird mark on the case. Send the gun back to Stoeger if this happens with different bullet brands.

This would get my vote too. I wouldn't think it to be a case of too large a firing pin hole with the amount of primer that is upset and no defined edge that would be imprinted by the edge of the hole.

Thank you for the input folks. I measured with a micrometer and I believe the firing pin hole is too big. Just for fun I
loaded one of the cases into the chamber and pulled the trigger a couple of times; the bulge was pounded flat and it looked normal.