Just purchased a Mark II TR rimfire to do some cheap shooting. Bought a Mueller scope, EGW 20 MOA scope rail and some Weaver brand 30mm scope rings. Got it all put together and the bottom of the scope bell was obviously to the left of the bore. Decided to shoot it anyway to check and basically ran out of windage adjust to the right at 50 yards. Thought WTF and flipped the rings around. Now the scope is right of the bore. My first instinct is that these scope rings are complete crap and machined wrong or something. Ordered a set of the TPS rings for and and am keeping fingers crossed. Is this a somewhat common problem? The rings came from Midway USA and were advertised as Picatinny rings but were in fact Weaver size crossbolts(which shouldn't have any bearing on the left right issue). The new rings are true picatinny crossbolt style and of much better quality.