I mounted one on a .257 Wby last night and had one hell of a time trying to get that POS working today. It has a zero stop mechanism that has to be unlocked using a 1.2 mm hex wrench. Who knows where the darn thing went? I imagine a gnat or maybe the wings of a range fairy blew it away? I didn't know they even made them that small? Searched all in the box to no avail. Ended up using a screwdriver from a set that folks use to repair eyeglasses. We tried to sight it in at 100 and it shot about a 1 inch group that kept moving around the target. So we told ourselves lets check it at 200 yards and we got a 2 inch 3 shot group 4 mils low, then a group 2 mils to the left and 3 mils up and so on and so forth. After 40 some odd rounds expended during the afternoon we gave up. Given the opportunity to purchase a Barska, or maybe an old Simmons over a Sig scope I will definitely go with either them before I spend another dime on a Sig optic. 
