View Full Version : "Sharpening" a Striker/Firing Pin

March 21, 2011, 10:31 PM
I'm trying to fix up an H&R 929 .22 revolver. It fails to fire once or twice each time I load up nine rounds.

It wasn't a super great gun when it was made, so I was told by a local gun shop owner that his gunsmith won't even work on them. Not enough payout for the time it takes, I guess.

Anyway, I've cleaned it throughly. I've checked the timing. It's marking the casings in the right spot. I'm not great at IDing light strikes, but I suppose that's what's happening. I switched ammo brands, and that helped a bit, but didn't solve the problem.

So my next step is ordering a new main spring. I did that today, so my next range visit should reveal something.

But my question is what's the next step? I'm assuming that if the main spring replacement doesn't work then I'd assume that the firing pin/striker is worn down. (Sorry if I'm butchering the the terminology, REALLY new to gunsmithing here. Let's just say the part of the gun that makes contact with the back of the casing). Is it safe to "sharpen" it?

Obviously, I don't want it sharp enough to puncture the casing. But can a run file down it a couple times to narrow it, therefore focusing the force on a smaller area?

Or is this idea something that will end up blowing up in my face... literally?

Thanks in advance for any advice.

March 22, 2011, 01:25 AM
Replacing the hammer spring is a good call. Do that, and test the weapon.

Before you do anything else, make sure the firing pin (or hammer) is not being blocked by debris, dirt, or worn parts, and is being allowed to protrude its maximum amount.

If it doesn't appear to be hanging up, or blocked by anything... keep moving.

You would be better served by tracking down a (new) replacement, than reducing the diameter of the firing pin (yes, that's the correct term).

The issue is more likely a worn firing pin, than a large diameter. Reducing the diameter is unlikely to get you anywhere, and could cause primer piercing issues (punching holes in the primers, so hot gases escape toward the shooter's face). :(

There are very few reasons to ever modify a firing pin, and nearly all of those reasons should involve a gunsmith.
....Which is where the pistol should probably go, if you find a replacement. Inexperienced home gunsmiths don't know how to properly check firing pin protrusion, and usually modify the pins improperly.

However, there may be some posters here that would be willing to walk you through it. ;)

March 22, 2011, 12:15 PM
Rimfire firing pins are not supposed to be pointy like for centerfire.
They have to be wide enough to squash (a highly technical term) the rim, where the primer compound is, and make the cartridge go off.
So, like as been advised, don't change the shape.
It would mostly likely make things worse.
If the firing pin is at fault, it's probably worn down some and needs replacement.

James K
March 22, 2011, 01:16 PM
That firing pin has a rectangular shape and yes, narrowing it is a common gunsmith trick to increase reliability. Just don't narrow it too much, you want it flat on the end, not sharp or pointy.


March 22, 2011, 05:45 PM
I completely missed that this was a rimfire (even though the OP said so in the first sentence :().

Change all my comments about "diameter" to width. ;)