MOA base for .308 needed?

[boobie]

Anyone know an estimate on the distance in which a 700 tactical in .308 would need a MOA base? Just looking for a wide ballpark because my range is expanding (so I will as well

)... I have a Mueller APT, but don't know the total MOA in it. Just curious. Thanks guys

 

[AXEMAN]

Re: MOA base for .308 needed?

just buy a 20 moa base no matter what. if you get a generic chart for a 168g it shows 451 +/- inches of drop at 1000y so if you had a 90 moa scope, the way it was explained to me was 45moa up/45 moa down. 45 moa = 451 @1000y but your erector tube will be all up against the top of your scopes tube. so, unless all that was BS, 90 is a generous amount of moa. but i still got a 20 moa base. thats just how it was explained to me.

your rifle will shoot to 1000 and beyond, its the scope, base and bullet you have to worry about to get you there. there is no real answer to the question the way you have posed it. but i hope this kinda answers what you wanted to know

maybe this will help. with a 0 moa base and modest scope, maybe you could dial out to 500-600? i really dont know as i am totally new to this, but ive been asking the same questions. and with a different bullet, like a 155 or 175 you may have enough scope and base to get further than with a 168. does that make sense?

 

[boobie]

Re: MOA base for .308 needed?

Yeah, that makes sense. Thanks for the help.

 

[longshotbml]

Re: MOA base for .308 needed?

Get the Badger 20 MOA base. You'll be happy.

 

[ORD]

Re: MOA base for .308 needed?

How much range you can cover with your scope depends on a lot of factors, including but not limited to: 1) the amount of int. adjustment in your scope (the Mueller APT 4-14x40 has around 80MOA); 2) which bullet/load you are using; 3) atmospheric conditions; 4) and so on and so on...

Without any cant to your scope base, assuming your zero is close to mechanical zero for elevation/windage of your scope, and using most common bullets/velocities, you will probably run out of adjustment around 900yds give or take.

My advice is get a 20MOA base. It keeps your adjustments more toward the center of the scope's adjustment range instead of at the extreme end when shooting longer ranges, it is there if you need it (just in case...better to have it and not need it than to need it and not have it), and the same money buys a 0MOA cant base as buys a 20MOA cant base so WHY NOT!?!?

 

[Tbag]

Re: MOA base for .308 needed?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ORD</div><div class="ubbcode-body">...better to have it and not need it than to need it and not have it), and the same money buys a 0MOA cant base as buys a 20MOA cant base so WHY NOT!?!? </div></div>

This does make solid sense.

 

[boobie]

Re: MOA base for .308 needed?

it does make solid sense. however, i do already have a 0 MOA base so i was pretty much just wondering at what distance i would need to upgrade to the 20 MOA. one person said 500-600, another said around 900yds. I'm looking to expand my distances, but the range addition is only to 800, and there are no others close by that go past that. If no one else knows for sure, I'll just grab another base to make sure.

 

[tullius]

Re: MOA base for .308 needed?

Get a 30, if your equip can still maintain a 100yd zero with it on.

 

[DirtyRod]

Re: MOA base for .308 needed?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: boobie</div><div class="ubbcode-body">it does make solid sense. however, i do already have a 0 MOA base so i was pretty much just wondering at what distance i would need to upgrade to the 20 MOA. one person said 500-600, another said around 900yds. I'm looking to expand my distances, but the range addition is only to 800, and there are no others close by that go past that. If no one else knows for sure, I'll just grab another base to make sure. </div></div>

Ameman hit it on the head. A .308 has plenty of velocity and range to get to 900 yards <span style="text-decoration: underline"><span style="font-style: italic"><span style="font-weight: bold">so it's going to depend on how much elevation you have in your scope</span></span></span>. The more elevation you have the farther you will be able to target. Assuming you still want to be able to zero at 100 yards, you need about 16-17MOA for 600 yards depending on your 168gr load, 21-22 for 700 yards, etc. if your scope has 40MOA of travel (20 up/20 down) you can get to 600 but will be just short at 700. If your receiver is drilled straight then you could use a 20MOA base to get to 700+ and and still zero at 100 but your scope would not have enough travel for a 30MOA base. If your scope has 90MOA of travel (45 up/45 down) you won't need an MOA base to get to to 900.

Get a ballistics chart. It will give you a good estimation of how much elevation you need for each distance and you can compare that to the elevation available in your scope. That will tell you how far you will be able to shoot with that scope on a 0 MOA base.

 

[SScott]

Re: MOA base for .308 needed?

Like was mentioned here, do some homework and find some balistics for the bullet that you are shooting, and compare it to your scope travel.
I shot my .308 5R at 1,000 yards for the first time last winter, I was using 168 grn Sierra matchkings with a 0 moa base and shooting my Zeiss 6.5 x 20 mil dot scope with a 1" tube. I ran out of elevation ajustment and had to hold using my lowest Mildot as an aiming reference. I was able to shoot that day, but I did learn what it is like to have the wrong gear, wrong bullet, base and scope. LOL
SScott

 

[DirtyRod]

Re: MOA base for .308 needed?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: boobie</div><div class="ubbcode-body">I have a Mueller APT, but don't know the total MOA in it.</div></div> If it's not in the scope documentation or on the vendor's web site then you can count the total elevation "clicks" and divide by 4 (1/4" adjustments). On a 0MOA base you get half of that for elevation. Or, you can call Mueller.

If you have already mounted it and zero'd the rifle then you can just turn it as far as it will go and read the turret. According to the Mueller site it's in MOA so that will tell you exactly how much elevation you have.

I assume this is your scope.

http://www.muelleroptics.com/products/MT451440

 

[TrooperBrian]

Re: MOA base for .308 needed?

I should have bought the 20MOA. I have the 0MOA EGW right now. At 100yd zero, my Nightforce is at 50MOA up.

 

[DirtyRod]

Re: MOA base for .308 needed?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TrooperBrian</div><div class="ubbcode-body">I should have bought the 20MOA. I have the 0MOA EGW right now. At 100yd zero, my Nightforce is at 50MOA up. </div></div>

If it took 50 MOA up from the mechanical zero to get a 100 yard zero you have some issues. Do you mean that the scope has 100 total and you are dead center? With a 0MOA scope that's about where you should be which gives you 50 up and 50 down. If that's not the case, it'd be checking the install and/or looking for different rings and base.

 

[Lindy]

Re: MOA base for .308 needed?

Yes. If the scope is installed on a flat base with the scope centered, i.e., it has equal amounts of up and down elevation, the line of sight should be parallel to the bore.

There are two angular components to a short-range - say, 100 yard - zero.

One is compensation for the height of the scope over the bore. That angle may be computed as:

angle = arctan (height above bore / distance to target)

In the case of my AI, for example, with a height above bore of 1.75 inches, at 100 yards (3600 inches) it's:

angle = arctan(1.75 / 3600) = .03 degrees or 1.67 MOA

The other component is the drop from the muzzle to the zero range. With my load at 100 yards, that's about 2.7 inches, or, using the same formula above, about 2.58 MOA.

Add those two up, and it's about 4.25 MOA or about 1.25 mil.

That should be all the elevation necessary to establish a short-range zero, unless there is something wrong with the scope.

 

[TrooperBrian]

Re: MOA base for .308 needed?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DirtyRod</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TrooperBrian</div><div class="ubbcode-body">I should have bought the 20MOA. I have the 0MOA EGW right now. At 100yd zero, my Nightforce is at 50MOA up. </div></div>

If it took 50 MOA up from the mechanical zero to get a 100 yard zero you have some issues. Do you mean that the scope has 100 total and you are dead center? With a 0MOA scope that's about where you should be which gives you 50 up and 50 down. If that's not the case, it'd be checking the install and/or looking for different rings and base.</div></div>

Not sure if I'm fully understanding your question. On a NF NXS 5.5-22x56, and a 0MOA base, the scope is set at 100yd zero at 50MOA up. So it would take me five turns down for the scope to bottom out, and I have about another 40-50MOA elevation up.

 

[DirtyRod]

Re: MOA base for .308 needed?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TrooperBrian</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DirtyRod</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TrooperBrian</div><div class="ubbcode-body">I should have bought the 20MOA. I have the 0MOA EGW right now. At 100yd zero, my Nightforce is at 50MOA up. </div></div>

If it took 50 MOA up from the mechanical zero to get a 100 yard zero you have some issues. Do you mean that the scope has 100 total and you are dead center? With a 0MOA scope that's about where you should be which gives you 50 up and 50 down. If that's not the case, it'd be checking the install and/or looking for different rings and base.</div></div>

Not sure if I'm fully understanding your question. On a NF NXS 5.5-22x56, and a 0MOA base, the scope is set at 100yd zero at 50MOA up. So it would take me five turns down for the scope to bottom out, and I have about another 40-50MOA elevation up. </div></div>

Sounds like you are in the middle of the travel range which is where you should be on a 0MOA base. Sounded like you were saying that you had some sort of issue. With 40-50 MOA of elevation left, you should have plenty of range left with most calibers unless you are shooting farther than 1k yards.