I have owned a model 75 that was converted to 22 WMR. It is feasable, and actually was one of the most accurate .22's I've owned. The bolt face will have to be opened with the extractor adjusted, the chamber needs to be reamed and the bolt throw(distance the bolt moves in the receiver from front to rear)had to be lengthened by machining the bottom rear of the bolt to allow it to travel further. I had mine done at Gene's Gunsmithing in Selkirk, MB. I do not believ e the model 60 would be feasable to do because of the problem with feeding the longer round fro the tube mag.