Pierced Primers


Hi Bruce.

Congratulations on a wonderful site and the only one that I’ve consistently visited over the last several months. I have a neat old Beretta Silver Hawk, 20ga, that I really love to shoot. Its NOT the new, big $ (for me), Silver Hawk. Recently, I’ve noted that primers are occasionally almost pierced by the firing pin and wonder if this is a huge problem that will cost lots of cash to have fixed? I see that the gun has grooves running down from the firing pin in the receiver which, I assume, is to vent gas in case of a burst primer??

Thanks,

Dave

Dear Dave,

Diagnosing gun maladies over the internet is a little like trying to operate a Ouiji board. It takes a lot of faith and dumb luck. I may lack faith and luck, but I have mastered the art of dumb, so here goes another guess.

Primers could possibly be piercing due to a poor run of primers or an improperly manufactured shell. That said, it is most likely due to worn firing pins which have developed a sharp edge. This may be due to normal wear or it might be due to some type of breakage.

You can examine your firing pins by taking the barrels off your gun and dry firing both “barrels” against a coin. You may have to flick the safety on and off once to drop the second hammer. This should leave the firing pins sticking out of the standing breech so that you can examine them. If one sticks out too far or has a jagged point, you may have spotted your problem. Firing pins are cheap and easy to replace, but if it is your first time, have your gunsmith do it.

The grooves you see in the standing breech running down from the firing pin are indeed gas vent grooves in case of a blown primer. Personally, I think that they are mostly for show these days as most guns don’t have them, but they don’t hurt anything and look sort of neat.

Speaking of grooves, primers and firing pins, this is a good time to cover guns that are hard to open due to firing pin drag. Firing pins are supposed to strike the primer and then rebound back flush with the breech face. Sometimes guns become hard to open after firing because the firing pin does not retract fully and remains partially stuck in the firing pin. This causes the pin to drag across the face of the spent primer when the gun is opened. You can easily spot this by noting a vertical groove scratched from the center of the primer downward to its lower rim. Depending on the type of action the gun has, this malady is fairly easily corrected by cleaning, new pins or new return springs. Just thought I would throw that in for those who have had that trouble. Ain’t this free advice stuff wonderful.

Best regards,

Bruce Buck
Shotgun Report’s Technoid
(Often in error, never in doubt.)

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3 Responses to Pierced Primers

  1. I thought that many middle and better grade guns had a ‘rebounding’ feature in the design of their tumblers and locks, so that the firing pins do not protrude after they have struck the primers: this feature being expressly designed to prevent primer drag and consequent harder opening of the gun?

    • Bill says:

      The Technoid mentions the rebounding firing pins. Rebounding hammers that eliminated the firing pin drag when opening are by no means a new invention because they came into existence about 1875.

  2. Steve J says:

    What a great site.

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