Originally Posted by cpttango30
To convert a 1911 45acp to a 22lr one has to change out the barrel recoil spring and the mag that is all. Swap them parts out and you have a 22lr or a 45acp.
Kimber and Ciener both make drop in slides where all you have to do is pull the 45acp slid off and drop this one in its place and swap the mags.
Converting a 1911 from .45ACP to .22LR requires a full top end swap, plus magazine and usually a slide stop.
Colt conversions work well. Here is a post war Service Model Ace conversion that drops onto any pre-Series 80 style full size Government Model, 1911 or 1911A1. The floating chamber approximates the recoil of a .45, which made it great for training.
The upper right hand (two tone) pistol in this pic is a Commander with a Marvel Precision conversion kit. That is an aluminum slide and does not feature the floating chamber. Very accurate, but no recoil. It uses Colt Ace mags with the slide stop notch ground off.