Answer

Simple, don’t convert such a nice gun to a .22. 🙂

Okay, light strikes aren’t uncommon with conversion kits for any handguns I’ve come across, and they generally end up being two issues that I’ve seen. First is simply ammunition used. Some commercial ammo has light strikes while other brands don’t. If the cartridge fires no matter how hard the strike is, the gun is likely in spec and the ammo is the issue. If the ammo fires most, but not all, the time, it’s still likely the ammo. Take measurements to determine the head space and firing pin protrusion and make sure the rim of the ammo used is thick enough to be struck and fire the primer. Also, a lot of these conversions work best with high velocity ammo, mine seem to like CCI and Aguila and hate Federal and other lower end ammo.

The second Issue I have seen, assuming you have run a few hundred rounds through to break it in and start the wear process on the parts, is the firing pin channel having issues. Usually really dirty or filled with dust and shavings that tend to bind the pin. Occasionally, you’ll see a burr on the firing pin channel or even the pin itself. Since these kits are basically the slide and upper components as a substitute for the standard slide/upper, you really don’t have a lot of problems with individual parts within them or out of spec parts, especially from SIG. On the AR conversions you can get issues with recoil and the pins fitting the upper/lower together, but the handguns don’t really have those same issues. In fact, most of the problems with conversion kits I see are failures to feed or eject since the magazines are sort of jury rigged to work with larger magazine wells, but I haven’t had much of a problem with SIG units.

You might also call SIG and ask, they’re pretty good about making these work right. Though I can’t say, in my experience at least, that .22 LR conversions have ever worked 100% on any firearm I’ve tried them on. My Kimber conversion kit for 1911’s works reasonably well and the Glock one works about average, my CMMG upper for ARs is finally tuned about the best it can run and still has occasional problems. The SIG one I tried on my P226 didn’t work well but worked great on a new P226. Of course, mine is an old police carry gun and rather abused over the years by a string of owners. My wife loves the SIG and can shoot the eyeballs out of Toxic Gnome targets with it, so I’ll keep it forever. 🙂 Jeff

Answer

.22 misfires would be addressed in the same manner regardless of the .22. Headspace, firing pin protrusion and or energy, firing pin strike placement on the rim, then of course the gun has to close…..i.e. feed correctly for the firing pin to hit the rim correctly. Keep us posted on your progress. Ken