I'm looking at the Marble Fiber Optic front sights for my Ruger Super Blackhawk Hunter in 45 Colt and wondering what "height" I should buy. I'm launching 279gr Penn Bullet Thunderheads at approximately 1200-1300fps. The sight options are set up for 44mag (.332), 454 casull (.310), and 480 ruger (.390). Suggestions? I will most likely move to 300+ grain bullets after running through the remainder of the 270gr I have on hand.