The VX-I is, simply put, the best scope in its class. No other riflescope will give you the performance and features which now include Leupold's Ballistics Aiming System for such a low price. The Leupold VX-I offers hunters Leupold quality and accuracy, affordability, and a lifetime guarantee for the money, you won't find a better scope, or a better warranty. The Ultra Slam utilizes the SA.B.R. (SAbot Ballistics Retical) system to deliver pinpoint accuracy at long ranges with today's modern muzzleloaders.