I have a Mauser 66 in caliber 8X68S, which came with an extra barrel in 7X66 SE vom Hofe. However, the 7mm barrel will not mate up with the action. It appears to be a simple question of relieving the barrel channel to accept the very slightly larger recoil lug, but I would prefer to have someone who knows what he is doing perform the job. Can anyone make a suggestion as to who that might be?