I am glad this thread was brought back to life as I had never seen this thread or conversion. I have done several dual caliber conversion by milling a recess in 45 colt cylinders. This also leaves a portion of the colt base exposed, but has never cause a problem for me even with stiff colt loads.

I don't think the above method of conversion would be that difficult especially with the new no pin extractors. A 45acp cylinder with chambers reamed to depth and a fitted colt extractor should do it.

A simple solution I had never thought of. I like it. I do like my cylinders with the full moon recesses though, because, I don't have to change anything, just load it with which ever.