Well, first I just asked to see if anyone actually had it done, or if it was just a stupid thought, but I am glad to see that they do that. I was thinking about having it done and/or ordering a gun and asking them to fit a barrel in a additional caliber before shipping. About how much did this cost? It seems like a great idea to have additional calibers with less cost, but I don't know the approx. cost yet, so that may not be true. Can any receiver get a barrel for any caliber? Anything else you think is important to add? Thanks!