How much is too Much MOA

[Ruger15151]

I currently have 2 F-Class rifles.... one has an action with O MOA built into the rail and the other has an action with a 20 MOA rail. I shoot both at 600 and 1000 yards

I am looking to purchase a NightForce Competition to shoot on both. I know I will need 20 MOA scope rings to get out to 1000 yards with the rifle/action with 0 MOA on the rail. However, if I use that same rings on the rifle/action with 20 MOA already in the rail, will the 40 MOA be too much for the scope for both 600 and 1000 yards?

 

[Warren Dean]

No. I use custom cut Farrell bases at 35 MOA and they work fine with my NF Competition scopes

 

[jepp2]

However, if I use that same rings on the rifle/action with 20 MOA already in the rail, will the 40 MOA be too much for the scope for both 600 and 1000 yards?

Depends. The NF Comp has 55 MOA elevation adjustment. How centered are you current scopes? In a perfect world, they would be perfectly centered, so you would have 27.5 MOA available. But this isn't a perfect world.

 

[XTR]

It varies with the rifle and scope. I have a R700 that the top of the action isn’t square and back when I ran a NF BR scope I needed a 30 moa rail, on any other rifle it needed a 20.

Then there is the possibility that the reticle isn’t mechanically centered on the elevation turret. (USO actually let’s you recover that with their EREK turret).

On my Panda and on my Defiance FTR rifles all 3 of my Comp scopes zero at 100 yds less than 1 turn (10 moa) off of the bottom of their travel with 20 moa rails. You may be fine with a zero rail. Zero it at 100 yds and see if you have 35 moa of up left, if you do t get a new rail.

 

[Ruger15151]

It varies with the rifle and scope. I have a R700 that the top of the action isn’t square and back when I ran a NF BR scope I needed a 30 moa rail, on any other rifle it needed a 20.

Then there is the possibility that the reticle isn’t mechanically centered on the elevation turret. (USO actually let’s you recover that with their EREK turret).

On my Panda and on my Defiance FTR rifles all 3 of my Comp scopes zero at 100 yds less than 1 turn (10 moa) off of the bottom of their travel with 20 moa rails. You may be fine with a zero rail. Zero it at 100 yds and see if you have 35 moa of up left, if you do t get a new rail.

Great advice but I need to buy the scope mount before I can check were it zeros. I have a defiance Ruckus wit 0MOA and a Borden with 20 MOA.

 

[Ruger15151]

Depends. The NF Comp has 55 MOA elevation adjustment. How centered are you current scopes? In a perfect world, they would be perfectly centered, so you would have 27.5 MOA available. But this isn't a perfect world.

Good point. I will have to check.

 

[Dusty Stevens]

I cant believe there have been responses without knowing the cartridge in question.

 

[Ruger15151]

I cant believe there have been responses without knowing the cartridge in question.

6BRA and 284 Win

 

[Dusty Stevens]

6BRA and 284 Win

Id scrap the 20moa rings if you have a 20moa base even though itll work fine with a nf comp

 

[Ruger15151]

Id scrap the 20moa rings if you have a 20moa base even though itll work fine with a nf comp

Thanks for the feedback but that wasn't my question. I want to use the same scope and rings with a 0 MOA action and a 20 MOA action. My question was if I mount 20 MOA scope rings to use on the 0 MOA action will they be too much when I mount them on a 20 MOA action.

 

[Dusty Stevens]

Id use it

 

[Eraser]

Thanks for the feedback but that wasn't questions. I want to use the same scope and rings with a 0 MOA action and a 20 MOA action. My question was if I mount 20 MOA scope rings to use on the 0 MOA action will they be too much when I mount them on a 20 MOA action.

I would say yes.
You have a total of 55min. you're going to take out 40min, that leaves you with 15min of elevation +/- if your centered in the reticle. Being centered in the reticle as close as you can is a big advantage, you'll get your best view through the optic.

 

[Ruger15151]

I would say yes.
You have a total of 55min. you're going to take out 40min, that leaves you with 15min of elevation +/- if your centered in the reticle. Being centered in the reticle as close as you can is a big advantage, you'll get your best view through the optic.

yes.. 40 moa in the action and rings won't be too much?

 

[Eraser]

yes.. 40 moa in the action and rings won't be too much?

I'm saying 40 moa is too much.

 

[lawman29]

XTR Signature Rings™ | Burris Optics

www.burrisoptics.com

 

[Goodcat]

The only downside I know of with too much MOA in mount or rings is the inability to zero at closer distances, or your zero would be near the end of your tube.

 

[NA Woody]

The only downside I know of with too much MOA in mount or rings is the inability to zero at closer distances, or your zero would be near the end of your tube.

this is exactly right.
You may run out of adjustment trying to zero at 100.

 

[Ray123]

I used 20 moa Badger Ordinance bases on a 308 Rem action with 155s 27" barrel velocity 2980 fps about 25 yrs ago and it got to 1400 yds with a 56 MOA total on the old Mark 4 M3 10X mildot scope.

 

[Turbulent Turtle]

Would I be right in assuming that you are using the 6mm at 600 yards and the 284 at 1000 yards?

Let's further presume that the 0MOA rail is the 6mm rifle and the 20MOA rail is the 284.

The NF has 55MOA of adjustment range. This means that on a 0MOA rail, you have 27MOA up and 27MOA down. If you need 9MOA to get to 600 yards, you're well within the range of the internal adjustments and you are still close to the middle of the range for best IQ, or whatever passes for IQ on an NF Comp.
(Just kidding, it's a good scope.)

On the 20MOA rail, your NF will have 47 MOA up and 7 MOA down. That should allow you to get to 1000 yards just fine if you need about 22=25 MOA to get there with your .284. This will have the NF close to the middle for best IQ, (or whatever passes for IQ on an NF Comp. Whoops, didn't I say that already?)
Also, you will be able to dial down to 100 yards with no issues.

If the above assumptions are correct, I would NOT use a 20MOA ring setup. If they assumptions are incorrect, I would rebarrel the rifles to make it right.