Is 20 moa mount really necessary?

I have an AR10 build in .308, 20” barrel, and have finally saved enough cash for a nightforce scope. Specifically the SHV 4-14x50 FFP with MOA reticle. With the wide range in adjustments on this killer optic, and the fact that I more than likely won’t shoot past 6-700 yds anyway, do I need anything like 20 moa mount? I like doing things once when possible and would appreciate some input. Yes, this has probably been asked many times but not seeing anything recent.

Thanks,

Billy.

Depends on scope travel and load data.

I can’t imagine limiting the distance a rifle will shoot by the mount the optics sit on. If you’ll go 6-700 then you’ll go all the way eventually. The first time I shot past 300 I rang the 1000 yard gong 20 plus times that day.

If you know for a fact you aren’t going past 700-800, you will never need that rail. To get to 1000 yards with a 178 started at 2550 you’ll only need 38.3 MOA. How much adjustment does the SHV have?

If you're looking to shoot at 600-700, you'll probably end up going farther. It wouldn't hurt anything to get the rail. I don't know the ballistics for your .308 round, but I had to get one for my 6.5 Creedmoor to reach 1,000. I was able to dial to 950 but I didn't have enough left to get to 1,000 so I had to hold over until I got the 20 MOA rail.

Specs say 90 minutes. Assuming that’s 45 on either side of zero?

Yes but your zero is rarely perfectly in the middle. I would assume 40moa of adjustment.

Put your bullet and expected velocity into a calc and see what the drop as it a variety of distances. Also remember depending on your reticle you can hold some more. I used to have a 24in 308 that I ran out to 1200 I bottomed out on adjustments so just used holds on the last little bit

All responses are appreciated. And make sense. I have some load data at home and will check. I handload so finding the right recipe will get done at some point. The hold over is 30 minutes on the reticle.

No

I've shot out to 1,100 on my 6.5 CM with a 0 MOA base and never even got to 11 mils (slightly less than 40 MOA). And you have extra hold on the reticle too.

Lots of folks say, "you'll go farther". It's not like there are 1,200+ yard ranges all over the place. I don't even know where one is within reasonable driving distance of my house. Besides, if you want to go far enough to use more elevation than that, it likely won't be on a 308 gas gun anyway.

what I was thinking too.

Exactly. So, let's calculate it. If your scope has 90 MOA total travel, a 0 moa base would put you in the middle with 45 up and 45 down. 45 moa available elevation on a 308 would easily get you to 900+, which is probably longer than you can shoot with that anyway.

If you added a 20 moa base, it would allow 65 moa total up (45 + 20) and allow 25 moa down, which is fine. But adding a 20 moa rail on top of the existing rail on the AR 10 would increase your height, which you would need lower rings. For your use, I would go with no rail, and get a set of high rings.

It's better to have it and not need it than to need it and not have it.

Not when it cost you in terms of ring height and ergonomics. JMHO

It can also save someone over a thousand dollars.

My SS 5-20X pulled duty on bolt action rifles for years, in a set of Badger Ordnance rings, and every bolt action has a 20 MOA pic rail. Installing the scope and rings on my AR-10 the scope was too low, of course. So I added a 20 MOA rail to the AR-10, and now the AR-10 doesn't have its' scope, same as my bolt actions don't have their own scope.

OP, if you plan on buying an additional rifle, you can let this scope work on two rifles, as long as you install the scope in medium rings, and install a 20 MOA pic rail on each rifle. I invertoried last week. I have 9 rifles I am using, and 3 scopes. Looks like it is time to buy myself another scope, but I will not be buying 6 scopes.

Going with a 20 MOA mount is a clean light option compared to a 20 moa rail. It is not going to hurt you with that scope.