Problem with my sxs not breaking open

[awaveritt]

I'm using my 20ga. CZ Bobwhite side by side in Cowboy Action shooting. On my first stage Saturday, I had fired both barrels and then discovered that the gun wouldn't break open for the last two shots of the stage. On closer inspection, I was able to "break open" the action by bringing the gun down on my knee. The primer on the shell coming out of the right barrel appeared to be punctured. I continued to experience this problem all the way through the match, having to break it over my knee, and each time at least one of the shells appeared to have the punctured primer. Is this an ammo problem, is my firing pin(s) too long? Ammo is factory Winchester AA skeet loads/9 shot.

[elk hunter]

More likely a firing pin problem. Too pointed, too small in diameter, flat sharp point. Pierced primers can leak gas back into the action and have been known to shatter a stock at the back of the action. Sounds like a trip to the gun doctor is in order.

[Dave Bulla]

I have a vintage German 16g sxs that did that when I first got it. Apparently two things caused it. First was too strong of a firing pin spring. I was told that the European ammo had harder primers so their springs are stronger. (No idea if that is actually true or not) Second was that there were no rebound springs meaning that when the pins went forward, they stayed there. When the gun was opened it would smear a crease down across the back of the shell for a little ways until the angle opened up. I had it all redone by a gunsmith and now it's fine. I wouldn't think a modern gun would have that issue with the excessive pin spring pressure though.

I'd drop the hammer on some empty chambers and open the gun slowly while looking close to see if the pins protrude at all to start. If so, that's your problem. If it looks okay, I'd next look to your ammo. If it's loaded too hot (handload issue only) it could do it. Also, and I doubt it's the issue as I'm sure you know better but firing 3" in a 2 3/4" chamber can cause those problems too. Just as firing 2 3/4 in a 2 1/2" chamber will.