Leupold two-piece steel bases fit right-hand and left-hand actions (available in front and rear reversible) and offer maximum accessibility to the breech area. the front base accepts a dovetail ring locking it solidly into position. the rear base accepts an adjustable ring which allows for gross left/right correction using the mounts. long-range STD mounts provide a 1/4-degree (15-moa) slope of built-in elevation.