scope mounts affecting MOA?

[fishblade2]

Hey guys, I recently was watching a video over sniping and the speaker stated that when a scope wouldn't reach the target he wanted because of running out of elevation he replaced the scope mounts with nightforce scope mounts. This increased his MOA. How is this possible? by the way if you can't tell i'm new to the concept of MOA.

also I was wondering, a person who bought an expensive enough scope would be able have the elevation needed or would you still have to get scope mounts that would help out with MOA?

Thanks for the help!

 

[Tim the student]

It just changes the angle of the scope relative to the rifle, so that you don't have to depend exclusively on the adjustment range of the scope. That's all.

 

[helotaxi]

The line of sight through the scope and the bore axis of the rifle must be at an angle to each other for you to actually hit what you see through the scope. As you adjust the scope for zero, you change that angle. What an angled base does is change that angle independent of the scope adjustment. In essence it adds the amount of angle in the base to the available "up" adjustment in the scope by offsetting the "zero" setting away from the center of the scope adjustment range. Basically after installing the angled base you have to dial the scope adjustment down to get the same zero that you had with a flat base.

Depending on the range that you're trying to shoot and the cartridge that you're doing it with, it is possible that no scope made has enough adjustment available. Realize that in a perfect world with a flat scope mount, you only have half the total scope adjustment available to dial up for increased range. So if the scope has 100MOA of elevation adjustment available, you can really only count of having a max of 50MOA available to dial in longer ranges. Adding a scope base with 20MOA of taper built into it would increase that available range to 70MOA.

 

[Fatelvis]

When you install your scope using a 20MOA base, you'll notice that when you go to zero it at say 100 yds (close range), you'll be cranking the turret down a lot, due to hitting very high on the target. (Assuming your scope's elevation is mechanically centered) This allows you to use some of the "down" adjustment in the scope's adjustment for longer distance. Hope this helped a little.

 

[Centurian22]

This explains it VERY well. Never heard it better.

http://youtu.be/Ppuzt3xv4Go

 

[Fatelvis]

You nailed it!