There are several 22 LR conversion units designed for 1911's in 45ACP. The following is my evaluation:
Original Colt - all steel, a plinker in terms of accuracy, floating chamber is a pain in the neck to clean.
Ceiner - a plinker in terms of accuracy
Jarvis/Tactical Advantage - all steel unit, better than the Colt unit in terms of accuracy, originally made by Jarvis, currently an improved model is made by Tactical Advantage, functions well with high velocity ammo.
Marvel - aluminum slide, does not stay open after last round is fired, outstandingly accurate and reliable with standard velocity ammunition, a favorite of bullseye pistol shooters.
Advantage Arms - an update on the Marvel unit with a steel insert in the slide which allows the slide to stay open after firing the last shot, accuracy depend on the model chosen, the target model compares in accuracy with the Marvel product.
Dvorak - an all steel conversion unit, highly regarded by the bullseye pistol community, i only tested one briefly so cannot comment on the specifics.
