Rifle Scopes How much elevation travel AR15?

[ASH556]

I'm not sure if the wording is clear, but here's the idea:

When shooting a scope on a long range bolt gun, guys typically use a 20MOA or 40MOA base so that they cheat enough adjustment into zero so they have enough turret travel to get them to longer ranges. Bolt gun optics are mounted much closer to the bore than AR optics.

My question is, how much of your elevation do you use up mounting a scope 1.5" above the receiver (like in a Larue mount) on an AR15? I'm planning to mount a Zeiss Conquest 3-9x40 on my AR. Zeiss says the scope has 64"/100yds of elevation adjustment. That's 32" up and 32" down from mechanical center. How many inches of adjustment am I likely to have after mounting on an AR15 flattop?

Thanks!

 

[Jon A]

Re: How much elevation travel AR15?

Expect to "use up" anywhere from 4-7 MOA just getting your 100 yd zero assuming everything is screwed together straight and true.

 

[ASH556]

Re: How much elevation travel AR15?

Thank you!

So that means with the scope mounted straight to the AR flattop, I'm out of elevation at about 400-450 yds. Another 20moa (canted riser) would allow me to push out to 900. Sound right?