zeroing issue with scope on AR15

[jlg]

I've mounted a Leupold VX-3 4.5-14x50mm scope on my AR15.

The problem I have is because the centerline of the scope is so much higher than the barrel (compared to a bolt gun) I have to dial the elevation dial way up to get it zero'd.

I'm looking for a 200 yard zero. From what I understand, on an AR15, if you sight in at 35 yards it should be close at 200. But I've more than 30 clicks and I'm still 2" low at 35.

Anyone else run into this problem - have a solution?

 

[taliv]

a 200 yrd zero will usually be very close at 50 yrds.

i'd recommend moving your rings back onto the upper receiver instead of on the rail and trying again

 

[TonyAngel]

Are you saying that you can't get it zeroed? Did you start with the scope at it's mechanical zero? Anyway, at 30 clicks, you've only applied around 7.5 minutes of correction, assuming that your adjustments are .25MOA. You've gotta do what you've gotta do to get it zeroed.

On the other hand, that whole sighting in at 25 yards for a 200 yard zero works with irons sights and red dots, but I don't know that I'd follow that logic with a scope like you're using. I'd suggest that you sight in at 200. If you have limited range, you should just sight in at 100, figure your dope or use a ballistics calculator and dial in for extended range.

This is a one piece rail, right? No gaps between the upper and forward rail?

 

[M1key]

The scope is about where the iron sights would be. So, a 50 yard zero should get you on target at 200.

BTW, I think that scope is a bit much for the rifle.


M

 

[jlg]

It is a one piece rail.

Scope is a bit much. It's my coyote gun. 4.5x does fine up close and the 14x helps me with my not-so-perfect eyesight on the farther shots.

 

[M-Cameron]

yeah, most scopes are 1/4" at 100 yards.....that means that at 35 yards, 1 click will only move .087".....so 30 clicks is only 2.6 inches.......so if you are still 2" low, another 30 clicks or so should bring you right up to center.

 

[rcmodel]

i'd recommend moving your rings back onto the upper receiver instead of on the rail

+ 1,000!
With your present ring set-up half on the receiver & half on the forearm rail it's hard to say what out-of-kilter elevation you have on the scope itself.
Put them both on the uppers rail, as far apart as you can space them, and still get proper eye relief on the scope. That will give maximum strength and support to the scope tube.

Height above bore has nothing to do with how much elevation you need to sight in at 35 yards.
Quite simply, your target is too close for a zero at 35 yards for it to be a zero at 200 yards.
If you do obtain a 35 yard zero, it will then be shooting about 5" high at 200, and actually zeroed at about 300 yards.

Assuming a 2.5" height above bore line for your scope.
At 35 yards it should be hitting almost 1" low for a 200 yard zero.
At 50 yards, it should be hitting about 1/4" low for a 200 yard zero.
At 100 yards it should be hitting about 1" high for a 200 yard zero.

rc

 

[TonyAngel]

Cameron, no kidding. I had a brain fart. Anyway, I'd still go for a 100 or 200 yard zero.

 

[jlg]

taliv & rcmodel, it is a VLTOR one piece upper receiver. This allows me to mount the scope out over the handguard without having to worry about twist.

Thanks for the input everyone.

I figured I could just keep dialing it up I just didn't want to use up all my elevation in case I ever wanted to try a much farther shot...although the likelyhood of me ever taking a shot, even at a steel target, out past 600 yards is slim to none so I probably shouldn't worry about it too much.

 

[taliv]

jlg, understand it is a 'monolithic' upper, and a nice one at that!

i'd still move those rings back. there are different schools of thought on ring placement. as rcmodel mentioned, some like to place the rings as far apart as possible, to minimize long, unsupported parts of the scope that would vibrate like a diving board under recoil. i like to place at least one of the rings against the turret.

nice stack of tannerite too

 

[Kwanger]

With a high powered scope like that - if you want a 200 yard zero, I'd go out and get a 200 yard zero. As the others have said, actually 50 yards is usually closer to 200, but there's no substitute for getting the actual far zero if your abilities and equipment are up for it.

With a monolithic upper of that quality, I would not be concerned about moving the scope back onto the 'receiver' if your eye relief is fine where you are. I might spread the rings out a bit for even distribution (as Taliv said, there are different schools of thought on that).

 

[jlg]

taliv, I see what you're saying now. I'll slide the back ring as far back as it will go.

I've got the scope right where I want it for eye relief.

 

[vanrichten]

Get a 20MOA scope mount for that thing and you should be good to go.

 

[Al Thompson]

Just went through this with a young shooter. We sighted the 50mm Leupold/flattop AR at 50 yards, no issues. Took a bit of cranking though.

 

[jlg]

Thank you everyone for the quick replies.

I'll take it back out this afternoon and keep cranking until it lines up. I've just never had a rifle that required that much adjustment.

 

[rcmodel]

Just remember what I said in post #7.

A 35 yard zero is not a 200 yard zero.

At 35 yards it should be hitting about 1" low for an approximate 200 yard zero.

rc

 

[jlg]

Thanks rc...I really appreciate your input.

I'll have a place to fine tune the sight in at 200 yards once hunting season is over...but for now I'm limited to about 35 yards.