i shoot with a Pentax Lightseeker and love them. imo the Light Seekers put the Leupold VXiii to shame. even the Game Seeker models seem clearer than the Leupold line (VXi-VXiii). i dunno how well it will do on a muzzle loader though, due to harsher recoil and the balistic plex lines are made for reference only on centerfires...not muzzle loaders.