Leupold Open Range, Rings, 30mm Med, Matte Black 180947 The Open Range series is a collection of lightweight 6061-T6 aluminum mounts built to outperform their price. With milled-in recoil lugs and low-profile keeper screws, Open Range rings firmly connect to both Picatinny- and Weaver-style bases. These Open Range cross-slot rings fit any riflescope with a 30MM maintube.