What MOA for my Lapua Scope mount

[Big Dad]

Hey Guys, Big Dad here with a confusing question for you extreme Long range shootest.....Last year my wife surprised me at Christmas with a Savage HS P .338 lapua. I have spent a year shopping for glass that I could afford and just bought a Vortex Viper 6X24X50 PST illuminated EBR-1. I really like American Defense scope mounts and am wondering what MOA (20, 30, 40?) Until a few years ago, have mainly been a Pistol shooting fool, so this long range thing is all New to my brain.
Any thoughts would be Great......

 

[vinson]

just bought a Vortex Viper 6X24X50 PST illuminated EBR-1. I really like American Defense scope mounts and am wondering what MOA (20, 30, 40?)..

That scope has 65 moa of total elevation adjustment, divide that by 2 and you are mechanically centered at 32.5 moa. You should be able to use a 30 moa base and make maximum use of your scopes travel. My 338 needs 80 moa to get to 2000 yards so this config or even a 20 moa base should get you there.

 

[Big Dad]

Vinson, thanks for the reply. As soon as I can get the scope mounted, will be zeroing in with Nosler Custom loads w/250gr. Accubond, then its all about reloading to obtain the sweet spot load. Just received 300rds of New Lapua brass, so will be looking for a good load as well.
Thanks again,
Big Dad

 

[rem338um]

Sorry ,,but last reply is incorrect....if the scope has 32.5 moa of up from center then you add a 20 or 30 moa base..that makes a total of 52.5 or 62.5 of up adjustment and that wont get you to a mile...mine take 70 moa to get to 1760 yards..you might make it to 1600 with the 30 moa base...just my experience talking.

 

[Big Dad]

Ok Rem, here's the deal. My Savage Precision came with a 20moa base, and I just picked up a set of American Defense Recon SL-30moa rings, so I am sitting on 50moa? Is this how it works. Gotta ask because this is All new to me......All the right advise I can receive makes Big Dad very happy.
Thank you for your reply.

 

[FEENIX]

Ok Rem, here's the deal. My Savage Precision came with a 20moa base, and I just picked up a set of American Defense Recon SL-30moa rings, so I am sitting on 50moa? Is this how it works. Gotta ask because this is All new to me......All the right advise I can receive makes Big Dad very happy.
Thank you for your reply.

IMHHO, Bruce puts it best ...

Even though the scope adjustment range may be large enough to get to 1,000 yds, you should use a 20 moa base. That's because off-axis optical aberrations that degrade resolution increase with incidence angle. You should set up your rifle so that the incidence angle is minimized for long distance shots (where resolution matters most).

Assume the base is within +/-10 moa of alignment with the rifle bore. Let's also assume your bullet drops no more than 30 moa at 1,000 yds, and you like to zero your rifle at 100 yds. With a standard base, you would need up to -40 moa of adjustment to get to 1,000 yds. That means you need a total 80 moa of adjustment.

With a 20 moa base you would need up to -20 moa to get to 1,000 yds, but up to 26 moa to get to a 100 yd zero (worse case boresight alignment in each case). That means you need a total 52 moa of adjustment. With a 20 moa base, however, the incidence angle at 1,000 yds is 20 moa less, so the image will have less blur.

 

[SidecarFlip]

At our age, just seeing 1000 yards is a challenge.............

 

[FEENIX]

At our age, just seeing 1000 yards is a challenge.............

I hear ya! This is my all time favorite ...