doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com HAMMER GUN/ STRIKER FIRING PIN QUESTION

I SHOT ONE OF MY HAMMER GUNS (A THOS. JACKSON LONDON UNDERLEVER) YESTERDAY AT SKEET; EVERY PRIMER WAS PIERCED BY THE FIRING PINS--BOTH BARRELS. AND THEY HUNG UP WHEN OPENING/ AND SOMETIMES CLOSING THE GUN. SO I FINISHED THE ROUND AND WHEN I GOT HOME, I REMOVED THE NIPPLES AND STRIKERS, CLEANED BOTH AND REPLACED THE SPRINGS (WHICH WERE ALMOST TOTALLY HOSED).
WITHOUT SHORTENING THE STRIKERS, I'M SURE THEY WILL STILL PUNCTURE THE PRIMERS. SO, ONE QUESTION: REMOVE MATERIAL FROM THE FRONT OR BACK END?

SECOND QUESTION: WHEN MAKING NEW STRIKERS, I THINK I WOULD USE SOMETHING LIKE 1080 OR 0-1 AND HARDEN ONLY THE FRONT END (TO MITIGATE DAMAGE TO THE HAMMERS)? OR BOTH ENDS?

THIRD QUESTION: WOULD THE INTERNAL PART (LARGER DIAMETER THAN THE TWO ENDS--TO LIMIT ITS TRAVEL) BE SEPARATELY MADE AND THEN TIGGED ONTO THE STRIKER OR SHOULD THEY ALL BE TURNED FROM THE SAME PIECE OF ROUNDSTOCK?
THANKS! GIL

Gil, make new springs for the strikers. I’ve used ball point springs cut to length. You might make them a little long at first and see how far the pins extend through when fully compressed. Last thing I’d do is shorten them—can’t put metal back on.

I recently made a new striker for my Scott and remembered someone on this board years ago suggesting using grade 8 bolts (found at hardware store) to turn down and not hardening. This is what I did and so far all is ok.

I am NOT a gunsmith so interested in other’s opinions.

Gil,
I agree with Joe about not shortening the firing pins. A late gunsmith friend told me many years ago that gun parts never get larger by wear...You might benefit by polishing any rough areas off the point, it should be round and smooth. I found from experience that it is folly to dimension firing pins so they stop hard by the receiver with the correct amount of protrusion. If it is not stopped by the primer, too much inertia is robbed by the receiver stopping it. As far as hardening, there are some steels that don't require it; but when required I try to harden so the front is spring hard and the rear chisel hard( to prevent mushrooming). You have to carefully watch the color run from the thick rear part to the smaller point, when "drawing" it. In other words so the point is blue and the rear is still "straw". Also, the strikers must not be too much smaller than the hole.
Mike

It is impossible to be definitive without seeing the item up close and personal but I suspect these are replacement strikers, perhaps even cannibalised from another gun, but definitely too long. If you depress the hammer fully onto the nipple, the striker should only protrude about 1.5mm from the breech face. If more than that it probably will pierce primers (providing the main springs are still sound) and very well may hang-up.
I would reduce the length at the primer end as there is obviously plenty of room to do so but you must make sure that the springs are not being crushed in their holes. It is this that tends to do for springs: if they aren't getting crushed or coil bound then they last much better. If the springs' working room is compromised then ease at the hammer end.
I would stress that without handling the gun's action it is difficult to analyse, so put your thinking cap on and work it out for yourself.
Remember, strikers are a consumable part and one shouldn't be too precious about them.
I make all my strikers from '12.9' cap head bolts (don't know if that translates) which doesn't need any heat treatment. It is quite tough to turn but gives a long lasting result. The whole pin is turned from one piece of metal, you do not need to weld on extra bits.

I've used Inlet valve stems for my Armi G Gamber hammer gun fired lots of rounds
I wouldn't use exhaust valves they are to brittle. It helps that I'm an engine reconditioner so have access to lots of valves