Thanks, But I've seen that vid and he doesn't take the barrel off. I also don't think his is held in the same as the Contour as I can't see the pin ours has.

I'm going to turn up a tool that will hold a milling cutter to face the barrel, and then another tool to hold a chamfering tool and turn up some brass 45 degree lapping tools.

This way I can do the job without spending £100+ on tools to do one job and also don't have to remove the barrel or anything. All the test pellets are now here and we'll be off to the indoor range very soon for some clinical testing and work.

I'll let you know how it all went.