I have a Sig P226R, and I bought the .22LR Conversion Kit. It consisted of the entire upper. I had so many Failure to Feed/Failure to Eject I consider it money wasted. It think it could be corrected with a stronger recoil spring, which of course is not available. This Kit was "extremely" sensitive to gunpowder residue to the point where it was hard to rack the slide, even trying numerous brands of ammunition. I bought a Ruger Mark III, SS, with the 4.5" Bull Barrrel and Crimson Laser Grip Combo. I don't get very many FTF or FTE, but I did get a lot of Failure to Fires that I would 'never' consider betting my life on it's reliability. Now, I'm a strictly Wheel Gun user, and I practice speed loading every day.