doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Firing pin length

I was shooting a newish SxS this weekend. It appears that one or more of the firing pins were dragging across the primers making the gun difficult to open. The pins are separate from the strikers. Everything went fine when I shot shells with soft W-209 primers but hard primer made the opening more difficult. Is there a "standard" length that firing pins should project through the breach face? I've heard something like 50-60 thousands.

muchatrucha,
What you said is pretty much standard,however the Sharps Borchart, as I recall, uses something like 35 thousanths, for the same problem you are having.Sometimes new guns,now,find their way out of the factory with less quality control than in the past.It may be that longer firing pins were used with the idea of adjusting them in a finishing/adjusting operation, which wasn't actually performed.
Mike

.055" to .065" on the protrusion. Do the firing pins have rebounding springs? They usually are present when the pins are separate from strikers, but not always. Also if the gun has a way of indexing the pins like a slot in them with a screw to keep them from turning, sometimes a slightly exaggerated radius on the bottom side of the pin will help it slide free from the primer pocket.

Thanks SKB. The gun has disc-set strikers so they will be easy to remove. I don't know if they are indexed, but I will look. Radiusing the bottom of the end of the striker tip will help IF they don't rotate within the disc. First I'll measure the protrusion, then their overall length so I know where I started. It was interesting to note the effect of different primers on my ability to open the gun.
Go figure..........

For all of us to learn and observe if you don't mind... What brand were soft and which were hard....
My Guess Remingtons were the softest...

Gerald: All I can tell you is that the Winchester shells with silver-colored primers were the culprits. Winchester shells with brass-colored primers worked just fine. My only explanation is that the later Winchester 209 primers were softer and therefor released my firing pins easily. Go figure........

In My Opinion, it may be the soft ones which present the problem on opening. First they will indent deeper & then 2nd the softer ones will present more frictional drag to the pin than the harder primer. As Russ used to say though "I could be wrong".

On a 12 bore the striker should protrude to a maximum of .068"/.072" .If they are disc set or loose then there needs to be some end float so I would make them to protrude about .050"/.055" "resting" on the hammers with the provision for them to come out to the full extent of .072" .
If the pins are dragging then it may be that the hammers are not lifting as soon as the gun is started to open , this could be due to ware in any one of several places or if the forend is loose . The cure will depend on the gun and where the ware has occurred .

I agree w/ 2-piper. The softer primer usually causes the problem described.
Firing pin protrusion,,I've always set them betw .035 & .045.
No chisel points to the tip. Nice semi circle polished tip.

It isn't that the primer necessarily needs an overly deep indentation to fire, but it does need sufficient energy in what strike it does take.
Anything deeper than necessary into a primer cup just buries the tip in there.

Even rebounding firing pins can get stuck in primers and make opening the action near impossible.

Couple that with what may also be a problem in the gun,,that being the cocking linkage having some loosness in it's take up as the bbl starts to drop open.

The hammer w/the firing pin down hard onto the fired primer isn't retracting as the bbls make their initial opening movement.
So the firing pin(s) drag across the primer as you initially open the bbls.

Depending on the wear or fit up of the linkage, some can be especially bad.
Add a soft primer cup and/or an overly long pin, it can end up being one of those over the knee opening specials when both bbls are fired.

I had a William Evans which was very hard to open when using reloads with WW 209 primers. Pronounced drag marks on the primers.
Switched to Cheddite primers, no more problems. WW primers were silver coloured.