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Old October 10th, 2021, 10:02 AM #1
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20 MOA Rail Confirmation

Please let me know if I'm thinking correctly on the installation of a 20 MOA rail...
Install 20 MOA rail with the thick part to the rear.
Install scope on rail and set to proper eye relief.
Lower the scope setting by 20 MOA.
Bore sight scope.
Take to range, establish zero and reset elevation knob to zero.

Do I have this correct?
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Old October 10th, 2021, 10:09 AM #2
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Correct

Just to be clear, you will be raising the recticle (lowering the POI) 20MOA
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Old October 10th, 2021, 10:11 AM #3
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Quote:
Originally Posted by Boats View Post
Correct

Just to be clear, you will be raising the recticle (lowering the POI) 20MOA
This was my thought. Thanks for confirming I was thinking correctly.
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Old October 10th, 2021, 11:06 PM #4
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What Boats said was correct you are raising the relative position of the reticle, but in order to do that, the taller part needs to be towards the front of the rifle.
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Old October 10th, 2021, 11:31 PM #5
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Quote:
Originally Posted by ToolAA View Post
What Boats said was correct you are raising the relative position of the reticle, but in order to do that, the taller part needs to be towards the front of the rifle.

The taller part of the rail needs to be at the rear of the rifle not the front.


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Old October 10th, 2021, 11:58 PM #6
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Picture artillery in the field. You're looking straight out across the battlefield through your sights, but the barrel on that cannon needs to tilt way up to lob that long-range shot.

Here's another of my incredible, award-winning illustrations.

Name:  20moa.jpg
Views: 281
Size:  21.9 KB
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Old October 11th, 2021, 12:54 AM #7
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Quote:
Originally Posted by rbird7282 View Post
The taller part of the rail needs to be at the rear of the rifle not the front.


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Agree.

When I'm sighting in my rifle I adjust the crosshairs to where the bullets are hitting. If they are hitting high, I adjust "up." At long range they will be hitting way low, so I adjust "down." At some point i run out of adjustment in the "down" direction. The only way to have the crosshairs go any lower is to have the scope tilted down.

By raising the rear of the scope 20 moa I've traded some of the excess upward adjustability of the scope for 20 moa more downward adjustability. This is done when I sight in at 100 yds and adjust "up" 20 moa to match where the bullets are hitting.

At least that's how I'm picturing it....
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Old October 11th, 2021, 03:26 AM #8
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Quote:
Originally Posted by rbird7282 View Post
The taller part of the rail needs to be at the rear of the rifle not the front.


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thats a big negatory, good buddy.

For starters, on most rifles, the screw spacing won't allow this.

Second, the up and down arrows on your elevation turret refer to point of impact, not recticle direction of movement. When you dial in a heaping dose of UP elevation, the recticle actually moves down (decreasing the distance between the cross hair and the muzzle, effectively raising the muzzle in relation to the cross hair, and raising the point of impact)

Hope this helps
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Old October 11th, 2021, 03:57 AM #9
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Quote:
Originally Posted by ToolAA View Post
What Boats said was correct you are raising the relative position of the reticle, but in order to do that, the taller part needs to be towards the front of the rifle.
You are physically raising the reticle position to bring the point of impact down by 20 minutes to counteract the installation of the tapered base with the tall side to the rear.

Please look at Occam's diagram.


Quote:
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thats a big negatory, good buddy.
Don't be a mud duck. Please look carefully at Occam's (correct) illustration above and re-think your position, and the position of your base.
Quote:
For starters, on most rifles, the screw spacing won't allow this.
True that most rifles' screw spacing differences won't let you reverse the base. Luckily...
Quote:
Second, the up and down arrows on your elevation turret refer to point of impact, not recticle direction of movement. When you dial in a heaping dose of UP elevation, the recticle actually moves down (decreasing the distance between the cross hair and the muzzle, effectively raising the muzzle in relation to the cross hair, and raising the point of impact)
True, but only serves to confuse new/unfamiliar shooters when mixed into "zero" conversations.
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Old October 11th, 2021, 05:43 AM #10
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On the rear. This way you use more of the whole scopes elevation movement. The fist time I mounted a scope I went back and forth in my head about it for sometime. It almost seems counter intuitive in some ways.
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