0MOA or 20 MOA?

[Buster95]

I have a .308 with a scope (30mm) with about 80 MOA of internal adjustment, do I need a 0 MOA or a 20 MOA base for 100 yds to 600 yds?

 

[accumark]

No more than enough unless there is some other problem causing you to not be close to center of your adjustment range.

 

[VinnyQC]

20 MOA is about 600m on a 308. So accumark is absolutely right that you have plenty of adjustment for your range, but if both bases are the same price, you might wanna go with the 20 MOA anyway, cause then it'll give you +20 to -60 instead of +40 to -40. Either way you're good for 0 to 600 yards, but if you somehow wanna extend your range you won't have to get a new base.

On the other hand if you want to add a red dot for close shots, then you're better off with a 0 MOA. If you wanna add a red dot for 600 yards shots (good luck with that...) then you'd need the 20 MOA.

Just my 2¢ anyway I think you're good to go with either base considering what you told us.

 

[tiriaq]

I have shot to 900, occasionally 1000m for 20 odd years, and never needed a 20moa base. I do use Burris Signature rings, should I wish to build some elevation into the mounting system. The 1000m elevation for my .260 w/139gr Scenars is about 32 minutes. .308 will be several minutes more.

 

[mebiuspower]

I have shot to 900, occasionally 1000m for 20 odd years, and never needed a 20moa base. I do use Burris Signature rings, should I wish to build some elevation into the mounting system. The 1000m elevation for my .260 w/139gr Scenars is about 32 minutes. .308 will be several minutes more.

I definitely will need more for my .50bmg. For the Hornady A-Max, if zero'd at 200 yards the bullet drop at 1000 is -226".

 

[tiriaq]

226" at 1000 yards is about 21 minutes. Your scope doesn't have that much elevation left after zeroing at 200?

 

[BigUglyMan]

I have a .308 with a scope (30mm) with about 80 MOA of internal adjustment, do I need a 0 MOA or a 20 MOA base for 100 yds to 600 yds?

Depends where your rifle zeroes. I had a 0 MOA rail on my 300 WM and my 5.5-22x Nightforce zeroed at around +70 MOA. Well that's no good if you want to push out past a grand. Had a custom +40 rail built for it. Now it zeroes at +30 MOA and there is a ton of room to reach out.

 

[accumark]

Depends where your rifle zeroes. I had a 0 MOA rail on my 300 WM and my 5.5-22x Nightforce zeroed at around +70 MOA. Well that's no good if you want to push out past a grand. Had a custom +40 rail built for it. Now it zeroes at +30 MOA and there is a ton of room to reach out.

Not sure but sounds like you may have issues with your scope or mount but that to me sounds wrong as to + 70 moa to get zero? most hope to be half of total elevation adjustment giving more that is needed to shoot distance he is looking to achieve.

 

[Bile]

...

 

[BigUglyMan]

Not sure but sounds like you may have issues with your scope or mount but that to me sounds wrong as to + 70 moa to get zero? most hope to be half of total elevation adjustment giving more that is needed to shoot distance he is looking to achieve.

The bullet went where it went and required the adjustment it required. In my case the adjustment put the zero at a place in the adjustment range that I wasn't happy with so I had a new base made. Rifles zero where they zero and most normal shooters wouldn't have the foggiest idea where it is in the range of adjustment. I did because I knew my scope had 100 minutes of elevation. The scope is bulletproof and worked fine on another rifle. In this case the place in the adjustment range where the bullets landed wasn't good enough. Easy enough fix. I probably didn't "need" +4- but I know I'm never going to have to dial to get it closer than a 100m zero but I'll damn sure stretch it out to where that extra 70 minutes of adjustment is going to get used.