Rifle Scopes Mount with MOA built in necessary?

[Cardboard Assassin]

I have a FFP Nightforce 7-35X with MIL-XT reticle on order for my new build and need a mount.

I`m thinking of getting a one piece unimount as it will make removing / reinstalling the scope easier if / when I swap it out for a SFP scope for F Class events.

My SFP scope is mounted in a unimount with built in MOA (20 or 30 - cant remember) which got me thinking if I want / need built in MOA / MIL in the mount for the new scope as the rifle already has 20MOA built in (Impact action).

Is it possible to have too much MOA built in? I read something a while back that it *could* be detrimental to the scope as it would be adjusted to the extreme for the most common sighting in distances (100 / 200) to counteract the cumulative built in MOA.

Is it possible that with too much MOA built in that it may not even be possible to zero at shorter distances as the scope may not have enough adjustment? I`d imagine this is unlikely as it is a 34mm and should have lots of adjustment.

Intended use is primarily PRS and if the centre dot allows enough accuracy F Class out to ~1000. Ive been looking at Spuhr mounts with 0 / 3 / 6 MILs built in but I am open to suggestion.

 

[Krob95]

I run 20moa on my AI AX and a 20MOA spuhr mount on my tangent theta. I am 1 mil above the very bottom of the usable elevation range. I’ve yet to see an issue with it. Ran 40 moa on my impact I had too with no issues. Maximizes the total elevation you will have

 

[Jef-in-AZ]

Don’t know off the top of my head how much adjustment is available in that scope, but you have two potential issues. First with stacking up 40MOA of elevation right out of the gate you may run out of adjustment in the scope. This applies to both elevation and wind age adjustment. My 1000 yard BR gun has this issue, closest I can dial is 250 yards, but since it spends it’s life at 600 & 1000 yards it’s a nonissue. The second potential issue is that the lenses in the scope will give the best images going through the center of the lens, and as we dial further away from that center point we use more of the edges of the lenses. This one however is more likely just an academic issue since you’re working with good glass to start with.

 

[hafejd30]

For what your intended use is (100 yard zero out to 1,000/1200 yards) you’ll be fine with the 20 MOA base and 0 MOA mount. With this combination you should have around 70 MOA of total elevation up with a 100 yard zero.

Only way I’d consider 40 MOA is on an ELR rig. Then I’d probably have a 300/500 etc yard zero to hang a bit away from the extreme end of the scopes elevation

 

[mrtoyz]

I have a FFP Nightforce 7-35X with MIL-XT reticle on order for my new build and need a mount.

I`m thinking of getting a one piece unimount as it will make removing / reinstalling the scope easier if / when I swap it out for a SFP scope for F Class events.

My SFP scope is mounted in a unimount with built in MOA (20 or 30 - cant remember) which got me thinking if I want / need built in MOA / MIL in the mount for the new scope as the rifle already has 20MOA built in (Impact action).

Is it possible to have too much MOA built in? I read something a while back that it *could* be detrimental to the scope as it would be adjusted to the extreme for the most common sighting in distances (100 / 200) to counteract the cumulative built in MOA.

Is it possible that with too much MOA built in that it may not even be possible to zero at shorter distances as the scope may not have enough adjustment? I`d imagine this is unlikely as it is a 34mm and should have lots of adjustment.

Intended use is primarily PRS and if the centre dot allows enough accuracy F Class out to ~1000. Ive been looking at Spuhr mounts with 0 / 3 / 6 MILs built in but I am open to suggestion.

You’ve got it right. If you have too much cant in your rail/mount combo you may not be able to zero.
I’ve always looked at the ballistics of my round (bullet BC, speed), the max distance I’ll think I’ll shoot and let the actual numbers make the decision.

 

[Steel head]

Depends on if you need the extra elevation or not for the distances you commonly shoot it.
My 223 has a 0.
My 260 has a 20.
My 7 saum has a 45.

 

[Cardboard Assassin]

Thanks folks. You have pretty much confirmed what I suspected.

Looks like I will go with a 0 MOA mount for the NF and the 20 MOA mount on my SFP will work nicely as I will be shooting F class at at 900+ when i switch to that so the extra MOA wont hurt.

 

[_Windrider_]

FWIW, I always use 20 as a starting point. I have only 1 rifle at 30 and 1 at 40.

 

[Slides]

The scope has heaps of elevation below 20 for 100 yard zero, even for my "cheap" 30mm tube zerotechs I have bought 40MOA rails. Why would you bother spending on a 34mm tube scope then wipe out a significant chunk of the usable elevation range by not zeroing close to the bottom when there is no difference in Mount cost? You don't need picture quality at 100 yards you are getting heaps of light from it, if you are worried about picture quality especially, you want it zeroed just off the bottom of elevation range so the lenses are closer to centre when using it out at 1000 yards or more. Likewise you need SFA windage adjustment in close but potentially a lot at longer ranges, zeroing close to the bottom helps with this too. You have the ability to shoot to ELR ranges with that scope if you set it up right the first time. Get a 9MIL/30MOA mount to add to the 20MOA of your rifle. If I mount a nightforce or March 34mm on my Lithgow LA105 it will probably go in a SPUHR 6 or 9MIL with level bubble, ON TOP of the 40MOA rail.

I am shooting F class targets with my 4.5-27 FFP scope, the 7-35 nightforce should kill it, if I was starting again I would have spent the extra on the 7-35 NF or a March 5-42.