I have a 10" .45 cal. muzzleloader barrel for the contender, has same sights ,looks just like any other bull barrel except for a small cutout on each side of the barrel at the back to relieve any pressure from the primer/powder blast. I've never had any evidence of any blackpowder getting into action and I use the real stuff, Goex 3F. Most accurate ML pistol barrel I've ever seen. I've been shooting it for , at least, 15 yrs. H08