It depends. It's pretty easy to change barrels on most semi automatics. They lift out for cleaning so if you have a damaged barrel you can replace it with a new one. Revolver barrels are usually part of the frame, but not always. In most cases you can't change them.
Its a revolver screw on with pin want to chsnge it back to 2 inch fro four
Thanks! Your answer is awaiting moderation.