MOA Scope Question

J

jim

Member
Hello - I have a scope elevation question I need help on. I am thinking of purchasing a Nikon Monarch 8x32 scope with 1/8 minute clicks which has a maximum internal elevation adjustment of 20 MOA. I am wanting to use it on a Savage LRPV in 223 with a 1 in 7 twist shooting Sierra 77 grain MK at 2800 FPS. My question is will this scope zeroed at 100 yards make it to 600 yards? I have a Sierra ballistics program that provided me with the following for the above combination;

Drop In Inches Bullet Path (1/8 MOA)

100 yards ----- (-2.36) ----------- 0.0
200 yards ----- (-10.08) --------- -14.7
300 yards ----- (-24.31) --------- -36.2
400 yards ----- (-46.53) --------- -62.2
500 yards ----- (-78.62) --------- -92.9
600 yards ----- (-123.05) -------- -129.1

My problem is I don't know how to calculate the math i.e., comparing the scope adjustments to my Sierra calculations. If I have the scope zeroed at the mid point of adjustment that leaves me with only 10 MOA up remaining. If this does not provide me with enough elevation will Burris Signature rings with the +20/-20 inserts allow me to make it?

I sure appreciate any advice on this - it will be good to know how to do the math!!
 
Yep your gonna need the inserts OR tapered basses.. Your 10 moa UP/DOWN adjustment will only get you 60 moa @ 600yds (if the rifle shoots to optical center @ 100yds.) less/more depending on impact from center. The Burris +20 - 20 combo (40 moa @100yds) will get you 240 moa at 600yds with the inserts alone. Although the +10 -10 sets(20 moa @ 100yds) would get you 120 moa @ 600 yds which I believe would be better. Then use the Scope clicks for the last 9 or so moa adjustments
 
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Jim

I just checked the specs for the Monarch 8x32 and it says 80 moa of adjustment! Assuming the scope is mounted somewhere near center that leaves you with 40 moa of adjustment up! That should be plenty to reach 600 yds.

Also, I would re-run your numbers again. I quickly ran it through JBM and it said 14.7 moa (92.4 inches of drop) to reach 600 from your 100 yd. zero. With the 123 you listed you would need 19.5 moa to get there. You should have plenty either way.

Here's the math involved to convert inches to moa.

Inches to MOA

Path (drop) / (range x 0.01) / 1.047= MOA

So for your example of 123 inches of drop at 600 yds.

123 divided by 6 (600x0.01)= 20.5
20.5 divided by 1.047 = 19.57 moa

and if we use JBM's example

92.4 / 6 = 15.4
15.4 / 1.047 = 14.70 moa

Hope this helps a little. Even if you just use the trajectory info listed on factory ammo boxes you can now change the inches of drop to MOA adjustments for your scope.

Sorry!!! I had the specs for the wrong scope!!!! Your are correct!!! The 8x32 only has 20 moa of adjustment. Your gonna need the Burris inserts or an angled base to get there!!!
 
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it's not just 'UP' you need to consider

jim said:
Hello - I have a scope elevation question I need help on. I am thinking of purchasing a Nikon Monarch 8x32 scope with 1/8 minute clicks which has a maximum internal elevation adjustment of 20 MOA. If I have the scope zeroed at the mid point of adjustment that leaves me with only 10 MOA up remaining. If this does not provide me with enough elevation will Burris Signature rings with the +20/-20 inserts allow me to make it?
Click to expand...

If you tilt the scope forward too much, you won't be able to get a 100y zero.

Figure a flat mount in most cases will result in a 100y zero above the midway point of the adjustment range. Let's say you end up with 7 MOA of remaining 'up' in that scenario. Now you use the Burris Signature inserts to tilt the scope down 20 MOA. What you've done is tilt the scope so that your 100y zero is now seven MOA below the bottom of your adjustment range.

That scope is suited for 100y to 300y shooting, unless you enjoy the fuss associated with trying to make such a limited adjustment range work for you. I wouldn't. :confused:
 
Yep!! I've got a Burris 8x32 and it only has around 20 MOA of adjustment!!!
 
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