I'd go with the Ruger .22 also.
I had a Colt Conversion unit that just acted...strangely. It was VERY finicky about ammo. With most ammo it was a jam-o-matic. It would shoot standard velocity lead .22 just fine although the documentation that came with it recommended against std vel. With the cheap Thunderbolt lead nose bargain ammo the floating chamber would lead up so badly tools were required to get it to come apart. Again strangely enough when the floating chamber was jammed tight and couldn't float the gun still functioned.
An article in the American Rifleman described my problem with the floating chamber saying a little metal could be polished off and the leading problem would go away. I let a gun smith take a try at it but I couldn't tell any difference after the work. Shrug. I think he was very leery of taking too much metal off the gun (an attitude which I respect) but I got a Ruger Mark II and never looked back.