I have a 300 whisper in a 15' barrel. I found it hard to hold, so I decided to make a barrel longer than 16' out of it. I went to Brownells and found a 30 cal brake that the outside diameter was larger than my barrel. Took it to a gun shop in Ruskin, and I had it installed. I then chemically welded it to my barrel. Since the gunsmith turned it to the same barrel diameter, I challenge you to tell that it was not part of the original configuration. Makes a dandy rifle.