What scope have you picked out? This is one place you don't want to go cheap as scopes take a beating on .50's, so much so that the internals will fall apart. Look to spend $1,000+ on a good scope for your rifle. The 20 MOA rail will help you get out to longer ranges, depending on how far you want to shoot a rail with more MOA can be added.

Other then that you got a great .50, State Arms/East Ridge are proven winners and have a great track record.

I hate to tell you this but there isn't a scope made that a .50 hasn't put the hurtin' on, even a Nightforce. While the expensive scopes do hold up better, time and rounds fired will tell how good a scope is, that and a companies customer service.

My NXS Nightforce has been riding my AR-50 for about 14 years now without a single problem and I wouldn't trade it for anything. Okay maybe one of the new NF ATACR or BEAST scopes. Whatever you buy be sure to stick with MIL MIL or MOA MOA when buying and understand how both work. Spending that kind of money isn't something to let go to waste from not understanding how it works. There's enough info online that will help you understand how to use it, heck you can download it to your phone and use it whenever you need to.

As to the BR Vs. NXS will come down to you whether or not you want to compete, the BR has finer adjustments but lacks the NXS elevation and windage adjustments. The ATACR is a NXS on steroids, bigger tube more adjustment better glass but it carries a BIG price tag. Think $2,500 or more and the BEAST is more then that so be sure of your needs. The other being, do you have a place to shoot it further then 100 yards?

I live in the high desert of SoCal and have shot my .50 out to 2000 yards because I know of a place to do it. That's where a good scope shines and a minor scope fails as it takes a lot to get there. Watching your round fly all the way to the target is amazing or someone else's if you're spotting for them. Another thing where good glass comes in, think of the movie the Matrix. Seeing a .50 round fly through the air will remind you of it once you see it and will amaze you as you watch the round fly.

Leupold scopes are good scopes, don't write them off if that's what you want. They will stand up to a .50 and have a good track record, plus Leupold has great customer service. I would stick with the Mk-IV line as they're more rugged and have more features not to mention more elevation and windage adjustments.

You'll want to use the max magnification if possible all the time but NF marks the scopes at a certain power to use the reticle as it was set up from the factory. If you change settings then you'll have to come up with new dope for the ammo you're shooting.

My NF is a 5.5-22x56mm NXS and is marked at 16X for the reticle to match the factory set up.

This may sound weird but 100 yards is actually to close as many people have said that the .50 round hasn't fully stabilized at that range. So the further you can set up a target the better, just remember to write down everything so that you can duplicate it again.