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-   -   Moa question (http://www.firearmstalk.com/forums/f65/moa-question-65586/)

elfmdl 06-01-2012 03:04 PM

Moa question
 
How much range will you be able to adjust for with a scope with 20 moa of adjustment?? This will be on a .308 Remington 700/

Sniper03 06-01-2012 04:43 PM

elfmdl,

That certainly is not much adjustment if your speaking on 20 MOA of Windage and 20 MOA of Elevation total. What dictates the answer to your question also depends on the dimensions of the rifle receiver it self. I do know with the Remington 308 PSS Law Enforcement Sniper Rifle using a Leupold 3.5X10 Tactical we had to add a 20 MOA Base on the rifle to get out past 700 to 800 yards. What kind of scope do you have?

03

elfmdl 06-01-2012 05:01 PM

I was looking at a Nikon but I think I have decided to go more for the bushnell line. Like a bushnell elite 6-24 with 50 MOA of adjustment. I could get a 20 MOA base if I had to

Txhillbilly 06-02-2012 07:31 PM

Quote:

Originally Posted by elfmdl (Post 821590)
I was looking at a Nikon but I think I have decided to go more for the bushnell line. Like a bushnell elite 6-24 with 50 MOA of adjustment. I could get a 20 MOA base if I had to

elfmdl,You also need to realize that the scope has 50moa total adjustment from top to bottom unmounted.If it was mounted perfectly centered with the bore(and it can't be),you would have 25moa of adjustment up or down.
Depending on your setup the scope center will be 1.5-2.5 inches above the centerline of the bore,so you loose several moa of adjustment.To gain back adjustment range,you use a + moa base or scope rings,that way it lets you have the ability to adjust the reticle for long range shots.

If you choose a scope with a 30mm main tube you will almost always have more adjustability from the start just from the bigger tube.
With some 1" tube scopes,and a +moa base,you can run out of adjustment range for sighting in the rifle at 100 yards,and you'd need a 200 yard zero,which isn't a big deal unless you don't have a 200 yard range near you.

Shoobee 06-02-2012 08:28 PM

1 Attachment(s)
Here is an example, to start with, from my own range card with my Nikon Monarch III 2.5-10x50 scope having an moa total limit of 70 moa together with my Remington 700 300RUM using 200 grain 3000 fps mv loads (B/C 0.395):

MOA / Range in yards

0.0 / 100

1.5 / 200

3.5 / 300

6.0 / 400

9.0 / 500

12.0 / 600

16.0 / 700

20.25 / 800

25.0 / 900

30.75 / 1000

Note that each individual click is 0.25 moa on my scope, and 4 clicks equals 1 moa. That's why the decimals in the moa's above are either .25, .5, .75, or 0 on the range card.

Note also that a 70 moa max limit means +/- 35 moa which is up or down. This is plenty for me, for out to 1000 yds, the magical military limit "back in the day" when Remingtons and Winchesters were being used by the military, before the days of the Barrett (which reach out to 2 miles or 3500 yds).

So to answer your question, for your rifle, a 20 moa elevation adjustment total maximum would allow you to adjust for bullet drop at a distance of

500 yards

because one-half of 20 is 10, and 10 moa is the correction just over a 500 yd shot.

That's plenty for hunting. My own longest shot on a deer is 425 yards.

I can't tell if you mean that 20 moa is the maximum internal adjustment (which is for the Nikon 8-31x50 scope) or if your adjustment up OR down can be +/- 20 moa (which is for the Nikon 4-16x50 scope).

Nikon Monarch III scope specs:

max internal moa / type scope

60 / 3-12x42

80 / 2-8x32

70 / 2.5-10x42

70 / 2.5-10x50

40 / 4-16x42

40 / 4-16x50

34 / 5-20x44

30 / 6-24x50

20 / 8-32x50

Got these stats off my instruction manual with the Nikon Monarch III.

When Nikon designs and manufactures these scopes, they must be assuming that the higher power scopes (anything over 10x) are going to be used for varminting. And variminting is normally done closer up on small game. Ergo not as big an moa adjustment required because within 500 yds the bullet is not going to drop as much.

They may also be assuming these high magnification scopes are going to be used for police work (another form of varminting, with 2 legged varmints) and as such the LEOs are normally going to be taking fairly close shots of 100 to 150 yds at most. Unlike the military, whose shots are normally at least 700 yds or more. Of course, the LEO sniper's target is the medulla oblongata, a bratwurst sized portion of the human brain, whereas military snipers normally aim for the heart, which gives them the whole chest as a secondary target.

That's probably why their high magnification scopes have such a small range for total moa correction.

Shoobee 06-02-2012 08:29 PM

Quote:

Originally Posted by Txhillbilly (Post 822752)
elfmdl,You also need to realize that the scope has 50moa total adjustment from top to bottom unmounted.If it was mounted perfectly centered with the bore(and it can't be),you would have 25moa of adjustment up or down.
Depending on your setup the scope center will be 1.5-2.5 inches above the centerline of the bore,so you loose several moa of adjustment.To gain back adjustment range,you use a + moa base or scope rings,that way it lets you have the ability to adjust the reticle for long range shots.

If you choose a scope with a 30mm main tube you will almost always have more adjustability from the start just from the bigger tube.
With some 1" tube scopes,and a +moa base,you can run out of adjustment range for sighting in the rifle at 100 yards,and you'd need a 200 yard zero,which isn't a big deal unless you don't have a 200 yard range near you.

I have never seen +moa bases for my rings. Learn something new every day.

I have seen moa gradations on a military or police scope, allowing you to center the target with the vertical hairline, and hold off with the horizontal hairline as high as you need to for the zero setting on the scope though.

Shoobee 06-02-2012 08:30 PM

Quote:

Originally Posted by Sniper03 (Post 821574)
elfmdl,

That certainly is not much adjustment if your speaking on 20 MOA of Windage and 20 MOA of Elevation total. What dictates the answer to your question also depends on the dimensions of the rifle receiver it self. I do know with the Remington 308 PSS Law Enforcement Sniper Rifle using a Leupold 3.5X10 Tactical we had to add a 20 MOA Base on the rifle to get out past 700 to 800 yards. What kind of scope do you have?

03

Sniper is exactly right, for obvious reasons.

:D

Txhillbilly 06-02-2012 09:04 PM

Quote:

Originally Posted by Shoobee (Post 822787)
I have never seen +moa bases for my rings. Learn something new every day.

Not bases for rings,I was talking about rings like the Burris Signature Zee rings that have different inserts to change the moa without needing a base.

I use these rings on all of my high $$$$ optics,they will never leave any type of ring marks on the scope tubes.

http://i999.photobucket.com/albums/a...gets/008-2.jpg

Shoobee 06-02-2012 09:30 PM

Very nice scope!

I just have an ordinary hunting scope. You set it once, and you live with it. Not so easy to dial-in adjustments afterwards. But it works for me.

elfmdl 06-03-2012 09:51 PM

Does anyone have experience with a bushnell 6-24 elite or know how many moa it has. I think I have found that it has a total of 50.


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