I find my scout scope mounted far up on the factory rail to be the perfect solution to the hammer clearance issue, no extention needed. My scope is
a 2.5 bantam Tasco. It is the perfect setup for deer. I am unconcerned on the cheap scope, because now sighted in it only shoots at deer. Although my Huntsman is the cheapeast rig of my muzzleloaders, it is the most accurate, and easiest to use. This scope arrangement for me is ideal.
Don't know why more folks don't go this way....