I wrote two articles on this web site, and in them I wrote about scopes. Bottom line: quality rail, quality rings and quality scope installed correctly! Having been around the block many times, I now use EGW rails and TPS rings on ALL my rigs. I have NEVER had to lap TPS rings, NEVER had any issue with EGW rails (and I use the aluminum ones).
It's sometimes, and buying scopes is one, better to spend a bit more for high quality and not worry about them failing you. The "for sale" area on this web site has some very good deals on quality used scopes. I've bought several Nightforce scopes on it at reasonable prices and they have always been like new. I'm guessing that you are wanting to shoot long range. Small errors at 100 are greatly magnified at 500 and more as the range increases! Incorporate a Vortex bubble level on your rig to keep from canting. BTW, the 20MOA rail doesn't cost any more and it still works fine at 100. Try to keep the objective bell as close as you can to the barrel, like a 1/4 to 1/2 inch. Your eye and cheek weld will get involved in that, so be flexible. Hope this helps!
