Put the unfired slug in another 20 ga and see what happens??? It looks like there is a clear difference of the firing pin strike in the pic though. Regardless that sucks!
Put the unfired slug in another 20 ga and see what happens??? It looks like there is a clear difference of the firing pin strike in the pic though. Regardless that sucks!
Phil if you have a micrometer or dial calipers mike the rim thickness and compare the one that fired and the one that didn't fire. Also check that the cartridge head is flat and isn't concave and that primers are similarly seated. If those checkout it pretty much eliminates a cartridge issue causing variable primer strikes.
It's the Gun. It's a common theme with the 220. Believe it or not, last year I had 2 buddies that their 220's didnt go off on a 140" buck and a 152" (that was later killed) on back to back days. They sent theirs to get fixed if I remember correctly.
Just a thought, is the deeper depression in the fired slug more of a result from the pressures of the shell going off? Or is it a direct result of the firing pin striking harder and deeper than the unfired shell?
On most guns, the firing pin will retract into the bolt face after hitting the primer and the bolt face should prevent the shell from coming back onto the firing pin. The exception might be on some older revolvers