This is the best place I can think of to post this since this isn't a normal barrel setup and I haven't heard back from a couple of smiths that I emailed. The barrel has a barrel extension which is basically hand tight so it can be reused but it's odd the way the barrel installs. It slides in from the rear of the receiver and there is a castle nut that is installed from the muzzle end that pulls the barrel into the receiver. I bought the tools and pulled the barrel so you guys can get an idea of what I'm talking about.

