Question: Scope Mount on AR15

[glock 357]

Been debating on scoping a spare AR15 I have. Curiosity had me out at the range today to try it out. However one problem and would like to hear from CG'ers who have experience with scoped AR15's.

Surprisingly this 20" Barrel I pulled from a service rifle is pulling MOA groups at 100yd w 75GR hornady match and RL15. However the eye relief is killing me. Per scope manufacture I am looking at 3.75" eye relief.

Picked up a scope mount recently that just wasn't giving me that eye relief i needed. So I head back to the store in Fremont I got it from. Once I got there, they mentioned I can push it further to the next picatiny slot. Which overlaps to rail.

I never mount a dot or scope on anything other than the receiver itself assuming the flexing of the barrel may tweak the mount. So is this normal? Will this work to overlap the one piece mount connecting to both the receiver and free float rail?

[jaymz]

Picked up a scope mount recently that just wasn't giving me that eye relief i needed. So I head back to the store in Fremont I got it from. Once I got there, they mentioned I can push it further to the next picatiny slot. Which overlaps to rail.

I never mount a dot or scope on anything other than the receiver itself assuming the flexing of the barrel may tweak the mount. So is this normal? Will this work to overlap the one piece mount connecting to both the receiver and free float rail?

If your barrel flexes enough to tweak the scope mount, especially an inch from the upper, you have a much bigger problem than a tweaked mount. Run it. You'll be fine.

[220]

That's close to how I'm running mine. Eye relief is more important to me than a bit of bridging. I really don't think it will affect zero at all either. Bridging individual rings would be a problem however.

[Fjold]

With a one piece mount it probably makes the barrel to receiver joint more rigid. I can't see it hurting you any.

[strongpoint]

The issue isn't barrel flex; the issue is what happens if the handguard gets loose and twists.

Yes, it's better to stay solely on the receiver. You want a cantilever mount that will push the scope farther forward. See if this page has anything that works for you (I use an ADM mount, which I highly recommend).

[OpticsPlanet]

I'd shy away from bridging that gap, a monolithic upper would work.

You might consider the Vortex ADR-X-30 mount, Vortex describes it as:

The extended 3-inch cantilever on the ADR-X provides an extra inch of offset compared to the ADR model and is best suited for scopes with four inches or more of eye relief.

http://www.opticsplanet.com/vortex-optics-adr-cantilever-mounts.html

Mark H.

[Dinosaur Jr]

I'd shy away from bridging that gap, a monolithic upper would work.

You might consider the Vortex ADR-X-30 mount, Vortex describes it as:

The extended 3-inch cantilever on the ADR-X provides an extra inch of offset compared to the ADR model and is best suited for scopes with four inches or more of eye relief.

http://www.opticsplanet.com/vortex-optics-adr-cantilever-mounts.html

Mark H.

This is an excellent suggestion!

[Merc1138]

If you have a 30mm tube scope, here's another option: http://aeroprecisionusa.com/aspx/sto...l.aspx?pid=207

[JohnCCW]

[sunborder]

Another vote for the ADM cantilever mount.