Re: Kimber .22 Conversion
There are two distinct and different reasons to use a conversion unit on a 1911 (or any centerfire pistol for that matter): Tactical and Target shooting.
For tactical you get to shoot huge quantities of 22LR ammo instead of expensive center fire ammo for practice. The Kimber, Ceiner, and others are excellent examples of tactical conversion units
For target shooting you can shoot uppers like the Marvel Conversion Unit No.1 which is probably the most accurate 22 LR pistol you can shoot south of the $2000 Olympic pistols. There are other target version too and all use the principal of the superior 22 pistols like the High Standard and the S&W Model 41. That is, the whole of the slide/barrel is solidly attach to the grip frame of the gun and only a small bolt moves in recoil. The sights stay in place on the frame as the bolt operates under them. These target conversion units easily meet or betters 5/8 inch groups (of at least 5 or more shots) at 50 YARDS (!) or at least the Marvel No. 1 does.
The great accuracy is why I chose to run a Marvel Unit No.1 on my 1911.