So I am playing with the idea of European style metal muzzle on my next wood gun build. I've looked at all the usual suspects, and trying to come up with ways to do it in a distinctive way.
This is my idea:
A section of 316 stainless tubing, that is cut in half into a half cylinder like the first image. The height of the half cylinder will be the same as the width of the gun at the muzzle. The inner diameter of the tubing will need to be the same as the height of the gun. The end of the gun will need to be perfectly rounded so that vertically it will mate with the inside of the half cylinder. The band slot will be cut from the very front of the gun. The section where the track goes to the end of the gun will need to routed out of the cylinder so that the shaft is only on wood. Finally, the metal will be held onto the end of the wood using two or four pins at 45 degree angles.
Rough sketch: