Ran out of elevation at 600yds

[Hengehold]

I have a Leupold VX-3i (1 inch body tube) and a Vortex 1 piece scope mount. I was shooting this on top of my AR15 at 600yds and ran out of elevation.

Is this normal to run out of elevation at 600yds?

is the only solution to buy a scope mount that has elevation built into it or am I doing something wrong with the scope?
-Trevor

 

[Turbulent Turtle]

I'm really not familiar with Leupold product in general and the VX-3i in particular. At the website they show some VX-3i with 30mm tubes and other with 1 inch tubes. For the ones with the one inch tube, they show 66MOA of adjustment range. That would be 33 up and 33 down at mechanical 0.

Even allowing for several MOAs to get to 100 yards, you should have plenty to get to 600 yards and beyond?

Could you tell us more about that Vortex 1 piece mount, and also the specific model VX-3i you have.

It should be easy to get a proper canted rail, if needed, but let's first look at the current setup and make sure it's all correct.

 

[Hengehold]

I'm really not familiar with Leupold product in general and the VX-3i in particular. At the website they show some VX-3i with 30mm tubes and other with 1 inch tubes. For the ones with the one inch tube, they show 66MOA of adjustment range. That would be 33 up and 33 down at mechanical 0.

Even allowing for several MOAs to get to 100 yards, you should have plenty to get to 600 yards and beyond?

Could you tell us more about that Vortex 1 piece mount, and also the specific model VX-3i you have.

It should be easy to get a proper canted rail, if needed, but let's first look at the current setup and make sure it's all correct.

Turtle,
Thank you for your input. I have now added some pics in with my original post. If the scope has 60+ moa of movement then I should not be experiencing this problem. I purchased this rifle/scope setup from another competitive shooter so I do not have any details about the model number/type of this scope mount.

The pics I added to the OP are:
1. Pic of scope and mount from both sides of gun. Marking underneath Vortex scope mount is “ADG”.
2. Pic of model markings on scope.
3. Pic of turret setting for 100 yd zero. As you can see, it appears to be extended out very far for a 100yd zero.

I hope this helps.
-TH

 

[chkunz]

I am using the same model Leupold scope as you with a similar AR configuration and do not have the problem you are having. So your mount/rail must be pointing more down than mine. The first thing I notice is you have the scope as far forward as it will go with your rail and mount. My rail extends out past the receiver further than yours does, but I do not know if that matters, again I think it has to do with where the scope is pointing. We are both using extended mounts.

 

[chkunz]

Another thought, If I were having your problem I would shim the scope. I have never tried to do this but I read many posts where people would do that. Make a simple shim our of the body of a coke can and try it. BTW for us southerners, all soft drinks are referred to as cokes.

 

[Turbulent Turtle]

After looking at the pictures, I have a few comments:

1- I have several scoped AR-15s and one AR-10. I have never installed the scope so far forward as you have it. The way I have them set is with the ocular lens just above the T-handle. In my days of Service Rifle competition, I used you have my nose at the T-handle, looking through the rear sight. I kept the same place for the ocular of my scopes, and pulled back my head a little bit.

2- The front ring of the one piece mount is way too close to the knob/erector set location. I never want the rings to be close to the bell, the zoom knob or the erector set/knob location.

Also, now that we have the proper model, it appears that it has 52 MOA of elevation, 26up/26down. If there is a problem with the mount, you might be close on elevation at 600 yards. You might want to check that the mount is properly installed on the top rail. Sometimes, they can be a little screwed up and are set up incorrectly. I would loosen the screws completely and then move the mount back and forth and side to side to make sure it's all good, then tighten up the screws a little bit at a time, front and back, front and back... I really would try to make sure the entire underside of the mount is on the rail, not just 3/4 of it like we see in the picture.

If that doesn't work, it will be time for a canted rail. Don't use home made shims; you'll only screw up the scope.

 

[palo]

I'm not familiar with ar15 type rifles but I have mounted a good few scopes on bolt actions.
I usually mount my scopes as low as possible and even at that I find I use more than half my elevation adjustment getting a 100 yard zero.
Your mount is very high which means your probably using most of your elevation adjustment to get your 100 yard zero.
A canted rail or lower mounts should sort out your problem.

 

[fkimble@charter.net]

Check your windage. How far of center is it? As you windage moves off center, it starts to limit your elevation. Somewhere on the web is a pic showing how the erector fits inside the tube. The farther to the side you go the less up/down movement is allowable.
I can see 7 lines on the vertical turrent, indicating you have 6 full revolutions of up travel. That should get almost any gun past 600. The scope mount is hanging off the front of the pic rail. It needs to be moved back for full contact of the clamp. Not sure this will change anything. As already mentioned, never clamp a ring that close to the turrents. I thing Vortex even mentions it in there lit. Several folks have sent Vortex's back to be told the rings next to turrents had damaged the erector limiting elevation. Maybe the original owner installed some type of limiter? Also what is your load? Very week ammo falls a lot sooner than full power loads.
Keep us posted.

PS have you contacted the previous owner for info?

Frank

 

[JFrank]

Yeah that’s not lookin so good.
I’m guessing you also have about 10 inches of eye relief, how’s the sight picture?

 

[Kracken McGraw]

From the pics it looks like the mount is making that scope run uphill from the parallel of of your rifle. Opposite of what your wanting.

 

[Hengehold]

Yeah that’s not lookin so good.
I’m guessing you also have about 10 inches of eye relief, how’s the sight picture?

Lol, Eye relief is not bad. The forward extending scope mount is commonly mounted on the front of the receiver in NRA highpower matches and CMP Service Rifle matches.

 

[SBS]

What palo said above ^^^. I've found that Leupold 1" variable power scopes usually need a little bit of help on elevation @600 yds. even with a bolt gun (mounts lower than yours). The higher you mount a scope, the more elevation you need and AR's are necessarily mounted high. A mount with 20 MOA should solve your problem.

 

[Hengehold]

What palo said above ^^^. I've found that Leupold 1" variable power scopes usually need a little bit of help on elevation @600 yds. even with a bolt gun (mounts lower than yours). The higher you mount a scope, the more elevation you need and AR's are necessarily mounted high. A mount with 20 MOA should solve your problem.

Thanks, this is looking like it is most likely the problem. Looks like I will need to get a new mount. $$$ Uggg.

-Trevor

 

[Turbulent Turtle]

Lol, Eye relief is not bad. The forward extending scope mount is commonly mounted on the front of the receiver in NRA highpower matches and CMP Service Rifle matches.

I can't understand why you would want the scope so far forward as this has the effect of reducing greatly the field of view through the scope. The further you are from the ocular the smaller the field of view. Perhaps that's the effect you're looking for to help you focus on the target. I think it's silly and it makes it very difficult to view the target as the smallest movement will throw off the picture.

Let me also correct another concept that is being articulated here. The higher the scope is located above the bore line, the LESS elevation you will need. @SBS has it exactly in reverse. If you want to see it for yourself, pop over to JBM and with your favorite ballistics, simple change the sight height to go from 1 to 2 to 3 inches and see what that does to the trajectory. In my case, I am playing with the ballistics of my AR-10 load with 175gr bullets. At 1 inch, I need 15.1MOA to 600. At 2 inches, I need 14.3MOA to 600 and at 3 inches, I need 13.5MOA to 600. With my load, each inch above the bore buys me 0.8MOA of elevation.

You will probably have seen pictures of ELR rifles with the scope installed a foot or more above the bore line. I don't think they are doing that to increase the elevation needed to get to their distance.

Here is a picture of my long range AR-15. I shot 1000yards F-class with that puppy.

 

[SBS]

I can't understand why you would want the scope so far forward as this has the effect of reducing greatly the field of view through the scope. The further you are from the ocular the smaller the field of view. Perhaps that's the effect you're looking for to help you focus on the target. I think it's silly and it makes it very difficult to view the target as the smallest movement will throw off the picture.

Let me also correct another concept that is being articulated here. The higher the scope is located above the bore line, the LESS elevation you will need. @SBS has it exactly in reverse. If you want to see it for yourself, pop over to JBM and with your favorite ballistics, simple change the sight height to go from 1 to 2 to 3 inches and see what that does to the trajectory. In my case, I am playing with the ballistics of my AR-10 load with 175gr bullets. At 1 inch, I need 15.1MOA to 600. At 2 inches, I need 14.3MOA to 600 and at 3 inches, I need 13.5MOA to 600. With my load, each inch above the bore buys me 0.8MOA of elevation.

You will probably have seen pictures of ELR rifles with the scope installed a foot or more above the bore line. I don't think they are doing that to increase the elevation needed to get to their distance.

Here is a picture of my long range AR-15. I shot 1000yards F-class with that puppy.

I think we are talking about 2 different parts of the elevation equation. I understand that when you already have a scope zeroed at at given range, then the higher it is, the less elevation required for a longer distance -- simply because of the greater angle of the line of sight vs. the bullet trajectory. The problem is using up elevation to get that initial zero @ 100 (or other distance) before you start cranking it up -- due to more distance between the line of sight and the bore. Using the example of the ELR rifles, if extending the height would get them on target at, say 2000 yds., then just simply making them higher would work and they wouldn't need the 40 to 60 MOA bases that they use. If higher bases alone would get you out to 1000 yds. for example, no one would be using the 10, 20 and 30 MOA bases I see used on the line. When mounting scopes much higher above the bore (like on AR's), you use up a lot more of the scope's elevation adjustment to start with and having a more acute angle on the line of sight does not compensate enough for it in many cases.

 

[284winner]

View attachment 1187066 View attachment 1187065 View attachment 1187063 I have a Leupold VX-3i (1 inch body tube) and a Vortex 1 piece scope mount. I was shooting this on top of my AR15 at 600yds and ran out of elevation.

Is this normal to run out of elevation at 600yds?View attachment 1187064

is the only solution to buy a scope mount that has elevation built into it or am I doing something wrong with the scope?
-Trevor

I believe the scope sits much higher than typical scopes do on bolt guns taking some internal minutes from the formula. I believe you need a 20/30/40 MOA rail. Whatever size fits your range of shooting.

 

[Hengehold]

I can't understand why you would want the scope so far forward as this has the effect of reducing greatly the field of view through the scope. The further you are from the ocular the smaller the field of view. Perhaps that's the effect you're looking for to help you focus on the target. I think it's silly and it makes it very difficult to view the target as the smallest movement will throw off the picture.

Let me also correct another concept that is being articulated here. The higher the scope is located above the bore line, the LESS elevation you will need. @SBS has it exactly in reverse. If you want to see it for yourself, pop over to JBM and with your favorite ballistics, simple change the sight height to go from 1 to 2 to 3 inches and see what that does to the trajectory. In my case, I am playing with the ballistics of my AR-10 load with 175gr bullets. At 1 inch, I need 15.1MOA to 600. At 2 inches, I need 14.3MOA to 600 and at 3 inches, I need 13.5MOA to 600. With my load, each inch above the bore buys me 0.8MOA of elevation.

You will probably have seen pictures of ELR rifles with the scope installed a foot or more above the bore line. I don't think they are doing that to increase the elevation needed to get to their distance.

Here is a picture of my long range AR-15. I shot 1000yards F-class with that puppy.

here is A picture of me shooting my service rifle with a similar forward mounted scope mount. As you notice, my eye has about 2 inches of a relief or so Even though the scope is far forward on the receiver

 

[Turbulent Turtle]

I recognize the signature chipmunk cheekweld. I still feel it in my face, even after all these years away from Service Rifle.

Essentially you are trying to use the same hold on the rifle with the big scope, as when you are shooting SR with a small scope designed for that purpose. The heft of the Leupold is causing you to mount it in a precarious position and that's leading to issues.

When I transitioned from SR to F-Class about 14 years ago, I realized I had to change my hold on the rifle to acclimate a higher magnification scope and the fact it was all prone. I started F-Class with an AR-15 on which I placed a 26 inch Krieger barrel and ultimately a 36X Weaver scope. That's the rifle you see in the picture above.

There was no way I would be able to use any scope with higher than 5X magnification while using the chimpmunk cheekweld with my nose right at the T-handle in the days of peep sights. I extended the length of pull and placed my head a little further back and stopped trying to force my SR hold on a rifle that was no longer meant for SR.

It's a good thing I started with an AR-15, because I feel quite sure that I would have been kissed by the scope a number of times before getting acclimated to the proper hold, if this had been a .308 rifle. Old habits die very slowly.

 

[Hengehold]

Thanks to everyone for your input so far.
I counted my clicks from 200 yard zero to the end of windage and elevation adjustments today and here is what I found.

# of moa to end of adjustment from 200yd zero:

From top: 19 min

from bottom: 32 min

from right: 33 min

from left: 21 min


looks like the sight is relatively centered in the tube for my 200yd zero. Additionally, I have 19 minutes of elevation available to get my 6mm 105 hybrid (2800 fps) from 200 yards to 600 yards. 15 MOA should be more than enough which theoretically gives me a few MOA to spare.
So, all the numbers seem to suggest that I should be able to use this scope and mount out to 600 yards without any issues. The only thing I can think of is maybe the sight is not actually moving with each turn of the knob. So for example, perhaps I dialed the knob for 19 minutes but the sight is only moving for a fraction of that amount.

This seems like kind of a longshot to me but it is the only thing that I can think of. The obvious solution appears to be getting a mount with 20 MOA Built into it. But it would be nice to know if something is wrong with my scope. I suppose I will need to send it to Leupold for an assessment.

-Trevor

 

[SBS]

When I think I'm going to be close on adjustment range, I have always used an optical collimator to make sure the crosshair is still moving while I'm clicking up. I have had scopes that quit adjusting while the knobs were still turning. Another possibility is that you don't have true 1/4 min. clicks. I know Leupold makes fine scopes, but I have found some that were closer to 1/3 min. clicks and some were closer to 1/5 min. Many years ago, a Leupold exec. told me he wished they had bought the Micro Trac patent from Weaver when Weaver closed up shop in El Paso -- they had the opportunity, he said. You can check this also with an optical collimator or put it on a target with known size squares, being careful not to move the rifle in the rest when adjusting scope.