Gordy Gritter sells a Video on Chambering. I bought one some time back. He seems to have a connection with Grizzley Lathes. His video is pretty good.
There isn't a lot to chambering when one thinks about it, if they know how to run a lathe. One tip a friend gave me, which I will use is to cut the tenon threads backward. That is to say, turn the threading tool upside down and run the lathe in reverse, that-a-way the tool will feed away ftrom the shoulder. Works fine, I have tried it on a couple of practice tenon. It looks to me that cutting and threading an accurate tenon without messing up the shoulder is the toughest part to it. There are DETAILS though that need to be paid attention to; measuring being one of them and knowing what measurements to work to. I haven't actually done a barrel myself but have been present when one of mine was done and have watched several of the videos. Lets face it, a lot of people who are not Profesional Machinists are able to chamber good barrels so it isn't that tough to do. It does require knowing something about the process, however.
