Considering a Used Bushmaster BA-50 with a Nightforce BR Benchrest 12-42x56 that will be included. Pretty sweet deal, I would rather have the NSX for sure, but the price is right on the package deal for the BR.    
The scope was never mounted on the BA50..  Any advice on mounting this scope? And testing it?  
I will be new to this caliber and shooting 200 to 600 Yards mostly.. Maybe Down the road a bit, I would like to try 1000 But Not many options in Western WA.

The scope has some Dovetail Rings on it which are silver and there is no brand stamped on them, so rather than putting an adapter on them, I would be replacing them.
I am leaning towards: Burris 30mm Xtreme tactical rings, extra high, (at about $55) And I have read some good reviews & that they hold up well on a 50. Has anyone used these?  
Would these rings work with the NF scope and BA50 combo?
I would be spending a bit of funds on this package, keeping that in mind is there any current sales or promos in the $100-$150 range, for better rings? someone would recommend for this setup?  

Thanks in advance for any info

Are you set on rings, or is a one-piece mount an option? The top rail on the BA-50 doesn't have an angle to it so for longer range I think you'll want at least a 20moa mount. I used a nightforce 1.375" unimount but a Larue or similar would be great too.

Edit: Forgot to mention the scope is similar size to the one you're getting, a 56mm objective and you can see how close it is to the rail.

Nice.. That is a Sweet set up! I am inspired. Thanks for the info.
Are those difficult to install compared to 2 piece rings?  
Yes they are close, I have been reading about flex issues on some forums. You do not have to worry about any flex contact?   How is the performance on range? What are the range capabilities of this set up?

Well considering the current buy-in budget & with my schedule.. my learning curve will be a long one.. I was hoping to upgrade to a nicer set of rings as my skills & cash flow increase down the road a bit?
Any other startup/budget options you are aware of that would work on the BA-50/NF-BR combo?
(as of now I am putting  those 2 piece NF's at the top on my wish list :)

I use one piece mounts for all my scopes (except for a couple rimfire optics) so I'm a bit biased, but I think they're easier than aligning and lapping individual rings. Cantilever on the one piece mounts plus the option to have an angle built into the mount is a nice bonus.

I was looking at specs of the Benchrest which has an Objective outer diameter of 69MM (it has the adjustable collar which adds dimension to the scope?)
I can not find the outer diameter of the NXS 12-42×56? (Is that yours?) I can just see the 56 MM objective diameter listed for the NXS?

So IF the Benchrest model has a larger outside diameter? (still trying to find clarification on specs)
might I need the NightForce Unimount with 1-1/2" height ? (A221 model)   instead of 1-3/8" ?
Will the 1-1/2" even be sufficient for 69MM outer?

I have also looked at the Larue Quick Disconnects.. But I need to find out the proper height.. 1.5 or 1.53 ?
I  guess my budget saving "buy in" on rings is going out the window ?

Does yourBA50 fit in stock Bushmaster case with your Nightforce scope?  Find any solutions?

Thanks again

I replaced the foam on the stock pelican case, the scope is a nxs 5.5-22x56. I ended up taking off the front rail that goes on top of the hand guard because I was worried about it flexing into the scope objective (plus weight savings) but the receiver rail being that close hasn't caused any impact. The unimount is lightweight and durable but a larue mount is going to be just as strong and maybe a bit cheaper plus you can get them in quick release style, I'm using a larue mount on a different .50 with a vortex razor hd gen 2.

Difficult to remove front rail? Any chance that could have add structural support against barrel flex?
The Benchrest is 69MM, Your NF Objective Outside diameter is 65MM. so based upon your photo. my clearance would be even less, so I might have to to go with Nightforce unimount 1-1/2" ?

As far as a Quick Disconnect model, I spoke with LaRue who makes the 107 QD model for 50BMG which is 1.45 in a quick Disconnect, BUT Larue Custome Service stated I will only be able to sight properly with my scope 500+ Yards out? (I want to be able to shoot 200Yards)
Also, they stated that since the BA-50 Rail has 0 MOA (per BM) the 107 MIGHT or MIGHT not make flex contact.. but it will be close. And I read on another siitet that it definitely will hit the front rail.

They do have the A111 which is 1-53" ? But it is not designed for 50BMG & they would not advise the Quick Disconnect for the A111.  
But If I can trim the foam out on the BM case, I may not need QD.

So I guess I am still looking for a more definitive options on what rings will work for the BA-50 with a Nightforce Benchrest 12-42x56 scope? (which has a pretty large Objective Outside diameter of 69MM)
As of now, because of clearance concerns, I am leaning towards LaRue LT111 Non QD at 1.53" height (will give me .175 clearance)  OR the  Nightforce Unimount 1-1/2" (will give me .14 clearance) or the $55 Burris ultrahigh  (1.60 est .24 clearance)  

Has Anybody else mounted a Nightforce Benchrest model to their BM BA-50?  and could share your experience/solution?

Going with the Larue LT111 at 1.53" height no MOA. I consulted with Larue seems like this was their suggestion.
What do you think Range on this set up with no MOA built in?
Also Wonder if I will have to remove front rail with the added mount height ? Hard to do?
Any advice on mounting scope?   Do I need levels?