I have an M99 enroute and have a Burris Black Diamond to put on it when it gets here. I need a set of rings and am confused about the setup. I was about to buy a set of Badgers but the Barrett adjustables have my attention. Anyone familiar with these? What is adjustable on them? Are they "secure"? Can I use the rings to slope the scope in the same manner a sloped scope base would? Is this the primary purpose of the rings being adjustable?

The reason I ask is I am aware that the Burris scope is limited in vertical adjustment compared the the mega-expensive variety. Is the Barrett "base" already sloped?

I have asked Barret once via email and got a rather ambiguous, one line reply. Any real world advice would help. Thanks.

This is what I remember from helping someone else. The rings mount on the rail with a cross screw and then there are two bolts per ring to tighten the base once you set them.

It wasn't to hard to bore sight, pulled the bolt out and lined up the cross hairs at 100 yards then tightened down all four screws. You can bore sight at whatever range you want as long as the rings will adjust that much. Make sure you center your elevation on your scope before you start.

Get the barrett rings. That is what you need to get. For "bore level zeroing". What I mean by that is that you adujust the rings so that you have your elevation set to almost absolute down, a few clicks up. Not centered. Then zero your scope with the rings at 100 yards so you have all of your clicks for elevation up. This is discussed in detail in the 50cal Hard Target Insertion book. Get that as well.

Are they "secure"? Yes they are.  Make sure that scope is other wise you will buying another after a few hundred rounds. I would recomend a leupold or nightforce with a fixed power.

Buying a scope to save money will only cost you later. Trust I know this for a fact

have fun its a great rifle