Irons on 20 moa rail?

[LongRangeLefty]

What’s up everyone. I have a Ruger RPR with a 20 moa base. I enjoy shooting long range (out to 1000) with glass, but also like to shoot at 100 with irons. Could I install the sights on this rifle as is? On the 20 moa base? I realize I could get the flat base, but I’d like to be able to just QD the scope on the same base, and am not really interested in offset sights. Thanks!

 

[kRcu]

Do the sights have an adjustment for elevation?

 

[LongRangeLefty]

I would be looking for at least the rear sight to be able to adjust for elevation

 

[sandwarrior]

The 20 moa base isn't going to hinder you. That is, I assume you have a rear sight mounted on a picatinny and the front sight mounted out on the barrel. Separated like that, the rear sight angle won't be an issue.

Added:
In that scenario, the rear sight would have to have elevation. Or, the front sight be adjustable down.

 

[LongRangeLefty]

Ok. So both the front and rear sight cannot be closer together. As in, both mounted on the pic rail on top of the receiver

 

[sandwarrior]

Ok. So both the front and rear sight cannot be closer together. As in, both mounted on the pic rail on top of the receiver

What will happen is the rear sight will be tipped forward 1/3rd of a degree. You will still be able to sight correctly through it to the front sight. Given that you find a rear sight with elevation adjustment, it will still reach the elevation you wish.

Think of the base directing the centered scope down 1/3rd of a degree, as that's what 20 moa is. The parallax points the center of the scope down 20 moa. But, when the rear sight center and the front sight are matched at a given height above the centerline (parallel) of the barrel, there is no 20 moa in the adjustment. It's zero-zero. Bring the rear sight up 2 moa and technically it should about match a 100 yd. zero.

At super extreme ranges, the slightly forward tipped rear sight wil be very slightly low, but that is going to be a very long distance shoot. Mathematically, if you raise the rear sight one inch it will shoot .0006 moa low. In the case where your sight needs to rise .007" per moa based on a 24" sight radius, I doubt you will notice the offset. You would have to be making a shot using 143 moa to see even that miniscule difference.

Now, if both front and rear sight are mounted on one rail, and initial setting is center of bore to center of sight, then yes, the 20 moa would come into play. You would have to lower the rear sight or raise the front sight.

Added:
it doesn't matter the distance between the rear and front sight if they are independently mounted. The slightly forward tip of the rear sight won't affect elevation until extreme distances.

 

[Ledzep]

What he said ^ 20 MOA is pretty mild.

All you're doing is effectively inducing a sin(0.333), or 0.582% error in the elevation adjustment of the rear sight. You'd have to adjust to beyond 1000yd (42 MOA or so) to even notice that there was 1 theoretical click (1/4 MOA) error in the system. If you have 1 MOA clicks or 1/2 MOA, even further. You're never going to notice it.

 

[Dan Warner]

What do you plan to use for sights? You will potentially have a height issue by having the rear sight up so high. You may not be able to get your sight low enough to zero at 100. Mounted on a base atop a rail puts it quite a ways up from the C/L of the receiver, and depending on your front sight setup, you may simply not have enough travel.

 

[natdscott]

I recommend you look at the RPA Sight, and the Phoenix, as both of them are available in a direct-mount version for Picatinny rails.

If you already HAVE a rear sight, Warner and Lipski both currently make Pic-to-Redfield mount blocks, and Lipski makes a Pic-to-RPA Grooved block.

Stay away from rear apertures with a lot of shit attached to them. Remember always that they were designed for .22 rimfire recoil, so the more weight and leverage you add to them, the worse it is for recoil breaking/moving elements with centerfire rifles.

I recommend you stick to a Gehmann 510 with an aperture only or a 530 with aperture and 1.5x with diopter adjustment. Be happy with one of those, feel better about it standing up to recoil, and know that either one of those can be driven to 6-8" groups at 1,000 yards by a shooter that knows how.

 

[sandwarrior]

I guess I shouldn't overthink the issue. The Ruger RPR comes with a rail attached, 20 moa is standard. Shooting to 100. Your rear sight will not be affected if it is separate from the front sight. (rear on the rail and front sight at the end of the barrel)

If you go with some kind of sight that attaches to that rail with front and rear in the same plane (unit), then you would have to adjust down 20 moa.

Short answer, no it won't be affected.

 

[ChrisH56]

Ok. So both the front and rear sight cannot be closer together. As in, both mounted on the pic rail on top of the receiver

Yes you could mount the sights on the 20 MOA base on the receiver but they would be awfully close. I think you have a GEN 1 RPR and if you haven't changed your handguard, it would be better to mount the front sight on the pic rail at the end of the handguard. It will give you a longer sight radius. They make AR 15 front sights that are lower, designed to attach to the handguards. If you want a more precise sighting system (something more than a post front sight), you will probably have to find a front sight that will nount to the barrel itself.

 

[LongRangeLefty]

Thanks for all the responses and info guys. It’s greatly appreciated. I bought these last night...

https://www.amazon.com/gp/aw/d/B01AISP1KW

Gonna put my Samson rail back on and mount them up. I just wanted something cheap that I can bang away with at at least 50 yards if not 100. They flip down so I can slap my scope back on in 5 seconds

 

[LongRangeLefty]

It doesn’t say how much available moa they have..

 

[natdscott]

Oh.

 

[LongRangeLefty]

^ That sounds bad lol. Will they not work?

 

[natdscott]

No problem. I had a difference of assumption on your needs for irons, that's all.

-Nate

 

[ChrisH56]

Thanks for all the responses and info guys. It’s greatly appreciated. I bought these last night...

https://www.amazon.com/gp/aw/d/B01AISP1KW

Gonna put my Samson rail back on and mount them up. I just wanted something cheap that I can bang away with at at least 50 yards if not 100. They flip down so I can slap my scope back on in 5 seconds

These look like they should work but......(I know there is always a "but"), The only elevation adjustment on these sights are in the front sight. The rear sight only has windage adjustment. You can find some rear sights that are fully adjustable like this one. Here is an inexpensive one on Amamzon.
https://www.amazon.com/Ozark-Armament-Picatinny-Sights-Rifles/dp/B013TLZ45C

 

[sandwarrior]

These look like they should work but......(I know there is always a "but"), The only elevation adjustment on these sights are in the front sight. The rear sight only has windage adjustment. You can find some rear sights that are fully adjustable like this one. Here is an inexpensive one on Amamzon.
https://www.amazon.com/Ozark-Armament-Picatinny-Sights-Rifles/dp/B013TLZ45C

They say that has elevation. By the fact it has an elevation wheel, I would say it has elevation. The link says it has elevation in this sight.

This sight is a good example of what the OP is asking. If this and the front sight were to go on a 20 moa mono-rail, you would have to adjust elevation down. If this sight is placed on the rear bases and aligned with the front sight on a base on the front of the barrel, parallel with the bore, you would pretty much have a standard sight configuration.

 

[natdscott]

They say that has elevation. By the fact it has an elevation wheel, I would say it has elevation. The link says it has elevation in this sight.

This sight is a good example of what the OP is asking. If this and the front sight were to go on a 20 moa mono-rail, you would have to adjust elevation down. If this sight is placed on the rear bases and aligned with the front sight on a base on the front of the barrel, parallel with the bore you would pretty much have a standard sight configuration.

I think he was commenting that only the FRONT sight of that set has any ability to adjust elevation. The sight set linked and purchased is relatively crude, and at best, considered a BACK UP iron sight set.

The photo ChrisH posted is an A2 bastardization, but if it functions as well as an A2, is precise enough to be as PRIMARY sighting system.

Again...difference of interpretation on the usage of irons. Not a judgement.

 

[sandwarrior]

I think he was commenting that only the FRONT sight of that set has any ability to adjust elevation. The sight set linked and purchased is relatively crude, and at best, considered a BACK UP iron sight set.

The photo ChrisH posted is an A2 bastardization, but if it functions as well as an A2, is precise enough to be as PRIMARY sighting system.

Again...difference of interpretation on the usage of irons. Not a judgement.

I missed that in the intial post. Therefore, like you, had a different interpretation. I love having high quality sights on a rifle as both backup and primary if needed. Then again, it's good to learn not only being as precise as you can with battle, sights, but learning how to use them like battle sights for quick aquisition as well. Which says....Damn, I need to go and train better again!