Hi guys. would appreciate some advice or tips on what I am attempting. I have a badly rusted barrel that I want to stick in a lathe and cut down to 13.5 mm OD and then sheath with a carbon fibre tube and aluminium end caps. The breach end of the barrel must also be modified to fit into a JRA multi shot breach. I'm just a bit concerned that 1.5 mm off the barrel might be a bit much.