Scope Height / Scope Mount Issue on an AR Platform

This is my first experience with a high power, large objective scope. But now I have a scope height mount issue.

• The scope is NightForce SHV 5-20 x56 (30mm Tube)
o Eyepiece outer diameter is 1.69”/43mm
o Exit Pupil Diameter is 8.7mm at 5x and 2.5mm at 20x

• The scope mount is a Nightforce X-Treme Duty Ultralite One-Piece Magmount
o Mount height 1.375”

• The stock is a Luth-AR MBA-1 Rifle stock

The problem is that in order to get a good view through the eyepiece, you really have to get you cheek pressed into the cheek piece. It’s not easy to repeat and with ear protection and glasses on, even if you get your head aligned, your gear is messed up.


So I am looking at swapping out the mount get additional scope height. Here are some options:

• Nightforce X-Treme Duty Ultralite One-Piece Magmount: Height is 1.375 (Currently in use)
• Burris P.E.P.R Mount: Height 1.6
• SPUHR SP-3024: Height 1.89”

So, you guys who have experience with these kinds of scopes, what did you do? How do you manage scope height on an AR platform ?

I would look on Amazon or other outlets where you can buy the El Cheapo mounts.

For 25 bucks I just had a Monstrum AR scope base sent my way.

It’s a single maybe two use product , but handy when I’m testing out fitment with new builds or scopes.

Point here is for 60-70 bucks you can buy a couple or three of these light duty scope mounts in varying heights and try them out to see what works for you - then go for broke with the nice mounts you linked to.

It would suck to order a $ 250 mount and it not be what you want (in height)

I am wondering what is the typical height of scope mounts for an AR. This one is my Grendel and she is a distance rifle. My bolt rifles don't have this issue. And, you are right, I don't want to spend more money until I have a better idea of what is going to fit.

Standard scope height on an AR is 1.75”. If you do some research and math conversion with the rings, bases, or mount you are looking at, you can calculate exactly what height rings you will need to get. As you see, the rings that go on a bolt gun often do not work for an AR.

Most rings and mounts will list their height on their web site. If you calculate the height in inches you need, you can figure out the rings you need.

Hello Chad -

The one piece mount I got from NF was supposed to work with the scope on the AR. Unfortunately that wasn't the case - or at least it makes it annoying to shoot. And, I wasn't using bolt gun rings on an AR as I was to a degree aware of some of the differences and my bolt ring setups aren't made for Picatinny rails anyway. What I am surprised at is the significant height difference. I have been building or refurbishing bolt guns for years and am comfortable with them. However, being new to ARs, this one aspect took me by surprise... an so far each mount or set of rings I have looked at actually do have their height listed in the specs... I know amazing right.. !

StraitShot,
I've got a Leupold riser that is supposed to be about .56" in height made for the AR platform.

This came with another scope I bought and I never used it. I've got a Geissele one piece mount on my setup and really like it.

If this Leupold riser will work for you, let me know. I've had it advertised for sale but with a set of Leupold QRW rings, but can easily separate.

Pics with rings in first post.
https://texashuntingforum.com/forum/ubbthreads.php/topics/7597166#Post7597166

Just the riser.
https://www.leupold.com/scope-mounts/mark-1-ims-integral-rail-mount

Here is the link for the Geissele mounts in case you're interested.

https://geissele.com/optics/magnified-optic-mounts.html

Where are you located? Maybe someone has a mount you could borrow

TxBoss / David - thank you for your offer and input. Very much appreciated. I am in the Rockwall / Rowlett area, lots of guys from this forum are out here... one is just down the street from me.

I have a Burris P.E.P.R (parts from another rig) that should elevate the scope enough to make the rifle more workable. I am only using lite loads at this point anyway to break in the barrel (yes I am one of those) and get to know the rifle. It is a form of heresy to wrap a $90 mount around a NF SHV 5-20 and somewhere the universe is now tearing itself apart..... but it's only temporary anyway. My intention is to make this 6.5 Grendel into a distance rifle. So I will search for a mount that has 20MOA cant to it -something that the NF mount didn't have in the first place. The example below is a SPUHR mount - nice and very pricey.... But I also have a NF Ultralite One-Piece Magmount to sell....


SP-3616

Allows the scope to be mounted 40 mm/1.57” farther forward than with a non-cantilever mount.

6 MIL/20.6 MOA
Height: 38 mm/1.5”
Length: 150 mm/5.9”
Weight: 242 g/8.5 oz


Early Grendel work - 5 shot groups... I like it so far...

Sounds like you're on the right track going with a taller mount. You don't want to crush your face down on the stock to get a sight picture. To drive an AR well, you need to be placing the butt of the rifle as high and as close to your body's centerline as possible. Then drop your face straight down on the cheekpiece, with as little head lean as possible. This usually means a taller scope mount works better.

Since you have an adjustable cheek piece and a large objective, I'd think you would need a cantilever mount that's at least 1.5". I wouldn't be too worried about getting a mount with 20moa cant built in. That scope should have plenty of travel to get you farther than the caliber's effective range.

Finally, a Spuhr mount is a great investment and you won't regret it. It won't do you wrong.

rock river has a 1.685 one piece for 60 bucks... RRA Hi-Rise Scope Mount, 30mm Rings, ITEM #: AR0131