Marlin mod 90 O/U
 

Went dove hunting over the weekend and my friends Marlin 90 O/U in 20 ga began to puncture primers on one barrel consistently. He was using low brass field loads. I havent had time to disassemble it yet but was wondering if anyone here has seen this before in this model. I googled it but found nothing.

Re: Marlin mod 90 O/U
 

You wont find that problem specifically for that model. What you do find is that problem across the board occasionally. usually its because of a worn breech face internally or worn hammer face. On floating pin models you can look to the firing pin retaining pin being the culprit or a broken firing pin spring.

Re: Marlin mod 90 O/U
 

I have a number of Marlin 90's and while I havent experienced primer perforation, I do have one that, while the breech face is correct, the firing pin is, as well, and the fp spring is also right, it strikes light (doesnt always go off) when using Remington factory shotshells. No other brand; just Rem's. Is there a possibility of "harder primer metal?"