I've had good luck with several makes of .22 lr conversions on a variety of 1911's: Ruger SR1911, Remington Rand WWll 1911A1, and four Colts. Marvel makes a good one, very accurate....Advantage Arms is good as well...Ciener's unit is as good as the above two, but must be kept pretty clean to function properly...and a Colt Conversion Unit with the old sliding chamber. Only the Advantage Arms unit will lock the slide back after the last round is fired. All have integral feed ramps tailored to their individual magazines.
Here's a cpl pics on a Ruger SR1911. Best Regards, Rod
Mavel on a Ruger SR1911
Advantage Arms on Ruger's SR1911
Ciener's Commander length unit on the same Ruger
Our Flag does not fly because the wind blows against it,
It proudly waves because a soldier's dying breath blows upon it.
USAF Forward Air Controller, 5th Spl Forces,
An Loc, lll Corps, RVN, 69-70, Vietnam Vet '69-'73