STOP! A bbl that "screws in" is a really tight fit. Unless you use the right tools, you will likely damage the receiver. You need a BIG vise with a padding block shaped to fit the receiver, and a barrel wrench. The wrench my smith uses is about 4 ft long. There are also some tricks about using moderate heat and penetrants. They did not want those to unscrew easily. My local smith charged me $35 to replace a 20 g bbl- including checking headspace.