Using a 20MOA rail

[erich505]

Sorry if this is too basic; but, I just can't find a good info source. So...

I'm put together my first LR rifle--Savage 6.5x284 w/ Nightforce ATACR F1 scope on top Nightforce rings and a 20MOA picatinny rail. Now, what do I do? I'm assuming that I zero the scope at 100, or 200 yards and then reset the elevation turret to zero without changing the crosshair position. I can then use my ballistics calculator, iStrelok, to estimate elevation corrections. But, there's a setting for "Zero Offset" in iStrelok. Do I need to put 20MOA in there or just leave it at 0 (my assumption).

If anyone could confirm my assumptions or push me in the correct direction, I would feel a whole lost better.

Thanks.

 

[FearNoWind]

Nothing is "too basic" my friend. Only stupid people don't ask questions.
You've described what I hate about those newfangled ballistics devices. They seem to be useful to the experienced shooter but get somebody new to the sport and all they do is confuse things.
I'd suggest you put that thing away for a while and get back to basics.
First, bed that 20MOA picatinny rail.
https://www.youtube.com/watch?v=d6RopWI0-GE
Next zero your scope to 200 yards. Get some reliable MV and BC data. If you're using bullet manufacturer's BC data reduce it by 7 - 10 percent.
Next, use an old fashioned ballistic calculator:
Ballistics Calculator - Hornady Manufacturing, Inc
https://www.federalpremium.com/ballistics_calculator/
Ballistics | Berger BulletsBerger Bullets
Take your rifle and dope sheet to the range, shoot it at 200, 300, and any other x00 range you have available.
Edit your dope sheet to reflect what's on target and go shooting.
Once you've got some real life 'In the field" experience with your rifle and scope then come back to that gadget. It's make more sense.
In a real time hunting situation by the time you plug all the factors into that gadget the game will have wandered into the next county.

 

[erich505]

Thanks for the support and excellent references.

I was maybe too brief in my original post--I had reviewed the bedding video and am ready to follow the example before fine tuning everything. I also have some recommended loads w/ 142g HPBT SMK bullets on top of new Lapua brass and 47.2g IMR 4831. I've checked the seating depth and am 0.050" off the lands. I chronographed at 2800 with virtually one hole for three rounds.

What I'm still confused about is the actual use of the rail. With the scope on top of the 20MOA rail, I zeroed at 100 yards just to get the feel of things. Now the elevation knob is 20 MOA up as expected. Question is, do I just take the knob off and make this setting the new Zero stop? I'm assuming that's what I do, but am looking for confirmation to put my mind at ease that I'm doing it correctly.

Again, thanks.

 

[jasent]

I think I'm understanding your Q

The 20 moa rail simply slants your scope 20 moa down to give you an extra 20 moa dial up. Once you have your scope zeroed to what ever range you choose that is your zero. Set your zero stop and you can forget the rail now. It will not come in to the equation again. The only thing the 20 moa rail does is make your scope zero out 20 moa lower in your dials capacity, example. Scope has 60 moa total adjustment but with out a 20 moa rail your scope will zero out some where in the middle range of the dial. This essentially wasted the 30 or so moa that's below your zero. So add the 20 moa rail and your scope zeros out closer to the bottom of the dials range adding more dial above your zero giving you more range in your scope.
Hope all this makes sense and answers your Q's

 

[erich505]

That's pretty much what I thought. But, couldn't find anything to confirm. You put my mind at ease. Thanks.