MOA scope adjustment question ?

[rmist]

I'm trying to figure out my basic elevation change for a Nightforce 15x55 scope (.125 moa click). Using JBM ballistic calculator says I need 13.5 MOA to get to 600 yards from a 100 yd zero. What do I input in my scope with a 20 MOA base installed?? Just trying to get close to be on paper at 600 yds. Has me confused at the moment !!
Thanx again
Rmist

 

[GSPV]

(20-13.5) * 8 clicks. Call it 50 clicks and give it a whirl. In your case, it's down, not up.

 

[Chuckhunter]

I'm assuming you are sighted in at 100yds, so if you need to come up 13.5MOA, divide 13.5 by .125 for your 1/8 min clicks.

108 clicks.

 

[rmist]

I had put in 52 clicks and had myself convinced it was wrong !! Just needed a rough adjustment. Thanx again
I had hoped I did it correct...
20-13.5= 6.5
6.5 divided by .125 = 52 (clicks)

Did I ?

Thanx again

 

[hogpatrol]

I'm assuming you are sighted in at 100yds, so if you need to come up 13.5MOA, divide 13.5 by .125 for your 1/8 min clicks.

108 clicks.

+1

 

[Wjesswheel]

Newbie here and I do not mean to confuse but I actually multiply (for most people I believe it's easier) 13.5x 8 = 108 is there any thing wrong with doing it this way? If there is please let me know

 

[Wjesswheel]

Also if I understand hi question once zeroed any elavation up or down has nothing to do with his 20 moa or even a 30 moa rail. If it cal for 13.5 up it on top of his already 20 moa rail. If this is not correct please feel free to bash me.

 

[GSPV]

He needs 13.5 total and has a 20 MOA rail.

The question is if it is already sighted in at 100 or not.

If it is, ithe 20 MOA rail is irrelevant and all 13.5 MOA are needed.

If the 20 MOA rail is new, and isn't already accounted for in the current sight in, the rail gives more than is needed and he needs to come down the difference between the 20 that he has by virtue of the rail and the 13.5 that he needs.

 

[rmist]

Yes...rifle was zeroed at 100 with the 20 moa base already installed. So it needs to go up another 54.

 

[GSPV]

Yep.

13.5 * 8 = 108

Sorry for the initial bad info. The 20 MOA rail discussion had me thinking that it was new.

 

[Wjesswheel]

If you zeroed with your 20 moa base at 100 and you ballistics is saying you need 13.5 to get to 600 then you need 108 totatally clicks to equal the 13.5 additional moa you need to get to 600. That sounds about right for my 308 with a 30 inch barrel for elevation I believe mind called for that and end end up being something like 13.2 but I am anewbie but I think I understand the math. If you zeroed at 100 with your 20 moa then you still need the 13.5 to get to 600.

 

[flatlander]

Dittos - if you zeroed at 100yds with the 20 MOA base installed, that 100yd zero already takes the sloped base into account, so you still need the full 13.5 MOA on your scope to get to 600yds.

 

[47WillysGuy]

Wouldn't it be easier to think in MOA's vice clicks to get on target. Call it a rough adjustment. 20-13.5= 6.5 MOA And save the precise clicks for getting from the 9 ring over to the X-ring?? 1/2 MOA or 4 clicks.

I'd probably loose count somewhere between 80 and 108 clicks and have to start all over. LOL! Precision! Precision!

 

[Wjesswheel]

Nice clear response. Haven't really done much dialing except for wind age just been holding over with my burris xtr 2 with 35 moa of holdover and just dial windage great scope so far, gets me right out to 1000 zeroed at 300, just a cheap plug for my less then upper shelf scope

 

[rmist]

Thanx again for your patience !!
After all this... dialing the moa will be in my future.

 

[mac86951]

I'm trying to figure out my basic elevation change for a Nightforce 15x55 scope (.125 moa click). Using JBM ballistic calculator says I need 13.5 MOA to get to 600 yards from a 100 yd zero. What do I input in my scope with a 20 MOA base installed?? Just trying to get close to be on paper at 600 yds. Has me confused at the moment !!
Thanx again
Rmist

Did you zero with the base installed? If so, come up 13.5MOA (13.5*8 clicks). If you zeroed without the base, then installed the base, it'll be more math and testing. Moving the distance of the axial bore of the scope to the axial bore of the rifle will change your point of impact, best to install the base and re-zero.

-Mac

 

[cat64]

If the 20 MOA base is accounted for as stated you need to come up 13 MOA and a half. If you have the 2013 model of that scope (5 MOA / revolution turret) simply count the numbers....go up 13 times ( namely two complete revolutions, plus three more to number 3) on your turret and go another half. The attempt to count clicks is rather tedious and prone to error. I shot the same scope and can very easy adjust to 1000 yards in no time. I agree though a zero stop feature on this scope would be great. To offset that I take a mental picture where the turrets stop when zeroed @100 yards.

Note: similar process is required if you have the 2014 model just pay attention to your numbers on the turret)

 

[M14AMU]

The 20 MOA base just allows you more UP adjustment once you're zeroed; don't even attempt to figure it in relation to what you need adjustment-wise from one yard line to another! I zero at 200 yards and then at every yard line and record the data! And as long as you use the same rifle, same load, depending upon the temperature....you will establish STANDARD CHANGES from one yard line to the next! I don't care for 1/8 MOA adjustments; nothing but a PITA!!

 

[dkhunt14]

If you are shooting competition like 600 yard you need the 1/8 MOA because the 10 ring is small and 1/4 MOA won't get you centered. It is the same in 1000 yard BR. Clicking MOA is no harder with 1/8 clicks then 1/4 inch. From one number to the next it is one minute. See how many minutes in a revolution. If it is 10 minutes per revolution and you need 21 minutes you just go 2 revolutions plus a minute. It is easy when you break it down too minutes and not clicks. Matt

 

[M14AMU]

If you are shooting competition like 600 yard you need the 1/8 MOA because the 10 ring is small and 1/4 MOA won't get you centered. It is the same in 1000 yard BR. Clicking MOA is no harder with 1/8 clicks then 1/4 inch. From one number to the next it is one minute. See how many minutes in a revolution. If it is 10 minutes per revolution and you need 21 minutes you just go 2 revolutions plus a minute. It is easy when you break it down too minutes and not clicks. Matt

I know how small it is but I've never had that problem! I respect your opinion however!