Light Firing-Pin Strike on Model 17-3

[AQBill]

Dear Fellow S&W Enthusiasts,
I have been greatly enjoying my recent acquisition of a K22 (17-3) and a K38 (14-3). On my last day at the range, I decided to try some different .22 ammunition other than CCI SV - SK Std+, Eley Sport and Aguila SuperExtra Std Vel. In each case, there was one chamber - the same chamber - with a light pin strike which resulted in an FTF. I switched back to CCI SV and although the strike was still light on the one chamber, it did fire.

Besides the obvious choice of sticking to CCI SV, what do you suggest I do? I do have the Jerry Kuhnhausen book but I'm not a gunsmith by any stretch of the imagination. Many thanks in advance.

AQBill

 

[tputto]

AQBill,

I'm not a gunsmith either but these are the most obvious things to check that have caused me similar trouble:

- mainspring screw should be tightened down. Its meant to be that way.

- the one chamber with FTF may be dirty and not allow the cartridge to fully seat, especially if the bullets bearing surface is of a different shape than CCI SV that worked for you. The firing pin energy would be lost in pushing the shell deeper and a misfire may result.

Do a good scrubbing with a brass brush, and check with a bright light that the chambers are totally clean. There could also be a burr in the chamber, check for that too.

If that does not help. something in the cyl.assembly may be bent, causing the chamber to be too far for the firing pin. You can check with a feeler gauge if the cylinder gap is the same for all chambers. If its not, my best advice is to take it to a gunsmith.

 

[scooter123]

- the one chamber with FTF may be dirty and not allow the cartridge to fully seat, especially if the bullets bearing surface is of a different shape than CCI SV that worked for you. The firing pin energy would be lost in pushing the shell deeper and a misfire may result.

^ This needs repeating. By design the energy produced by the mainspring is consistent between cylinder chambers. In fact the only way to change the energy produced in the hammer strike is by using your thumb to cause drag.

The 22 caliber is by nature a rather dirty caliber and using a load, the Long Rifle, originally intended for use in a Rifle just makes it even dirtier. BTW, I've been told that there is Long Rifle match ammo out there designed specifically for handguns but haven't ever seen "in the flesh" so it's easy to assume you were using Rifle ammunition.

Dirty ammo means dirty chambers and dirty chambers means that you will have difficulty pushing a fresh load all the way into the chamber. Since it's likely that one chamber is a hair different in size or surface finish than another it can be expected that difficulty seating a fresh round will show up on just one chamber initially. The result of a cartridge that isn't fully seated with a 22 rimfire is almost always a misfire.

 

[tomcatt51]

I agree with tputto and scooter about cleanliness. Chambers, rim recesses and under the extractor (star).

Chambers can be deceiving. 22s can leave hard carbon crud your usual brush and patches will just polish. I use powder solvent and a .243 rifle bore brush in a piece of cleaning rod chucked in a (variable speed) drill motor to clean them. Keep the brush and chambers wet with solvent. It's amazing how much crud will come out of a chamber you'd have sworn was clean.

DO NOT use the drill motor technique on anything other than the chambers.

 

[saemetric]

If you have ever watched the "pros" load and fire a revolver, especially a rimfire, they always run their thumb over the shells after loading the cylinder and before closing it. This action makes sure the cartridges are fully seated.