Warning

 

Close

Confirm Action

Are you sure you wish to do this?

Confirm Cancel
BCM
Member Login

Posted: 1/24/2009 7:20:55 PM EST
I just had a flat top receiver installed and I plan to mount a scope for varmint hunting.  The scope will have a 1" tube and I plan to use Burris Signature rings with the offset inserts.

These rings come in "med" and "high" sizes and I'm wondering if anyone could tell me how high the scope should be mounted to get me in a good height range for cheek weld sight alignment.

I have noticed that there are 2-piece risers that are about 1/2" high and 1-piece risers that are around 1" high.  Can anyone give me advice on what combination of these Burris rings and risers should get me where I need to be height-wise?

Thanks!
Link Posted: 1/24/2009 8:28:51 PM EST
To determine if the scope will fit we would need to know the bell diameter, not just tube diam.
Woops I just reread your post, um I'm not familiar with those risers... But i love my scopes as low as I can get them.
Link Posted: 1/24/2009 8:45:45 PM EST
On an AR, you generally need the risers, even with special rings. I have high mount rings on one scope, and it's still too low to work properly without them. Even though dimensionally it fits on top, the scope sits too low for a proper line of sight.

The biggest issue I had other than cheek weld was the front sight getting into the picture. It would appear as a dark blob right over the reticule when the rings were used by themselves.
Link Posted: 1/25/2009 5:15:01 AM EST
The "standard" height for mounting a scope on an AR is 1.40" above the rail.  Thats the same height as an AR iron sights, and works for most people.  That doesn't mean something else wont work, but chances are that height will work.

You can get there with rings alone, or with shorter rings and a riser.  Leupold defines their ring height from the flat top to the centerline of the ring.  Burris defines their height from the flat top to the bottom of the lower ring and you have to add in the radius of the scope to get the total height.

Both Burris and Leupold have individual rings––they call them "ultra high, or super high, or whatever" of 1.40".  The Leupold rings are pretty pricey and the Burris quite a bit less, with others even less than Burris.  Check out the Larue sight, and specifically the LT-104 which is pretty expensive ($200) but does allow the scope to be mounted further forward for better eye relief.  There are other cantalevered mounts that are less expensive, and there's a very good thread that's been running recently that presents all (most) of the current cantalevered mounts.

You can get to 1.40 inches with shorter rings mounted on a riser. Its simple arithmetic to get the total height.  You need to know the actual height of the rings you're buying––not just the manufactuers designation of low, medium, high, etc.  The Midwayusa catalog does a good job of listing the actual dimensional height of the rings they sell.
Link Posted: 1/25/2009 5:19:52 AM EST
I would get super high rings that would work without risers or a 1 piece mount like an Armalite.  Larue's mount would work too but quite a bit pricier.  When I see risers I think .
Link Posted: 1/25/2009 6:03:08 AM EST
Thanks for the help.  I do have one clarifying question for you.

You mention that Leupold measures to the center of the scope/ring and Burris measures to the bottom (thanks, this is good to know).

My question is, which method are you using to get to the 1.4" mentioned?  Is that 1.4" from top of rail to center of scope/ring?

Thanks again.
Link Posted: 1/25/2009 6:14:17 AM EST
Quoted:
Thanks for the help.  I do have one clarifying question for you.

You mention that Leupold measures to the center of the scope/ring and Burris measures to the bottom (thanks, this is good to know).

My question is, which method are you using to get to the 1.4" mentioned?  Is that 1.4" from top of rail to center of scope/ring?

Thanks again.



Yes––from the top of the receiver rail to the centerline of the optic, or stated another way, from the flat surface of the lower ring dovetail that sits on the rail to the centerline of the ring. Obviously, the same thing. Its easy to measure if you have the lower ring in hand––with a flat layed across top of the lower ring, measure the distance with a machinists scale or someting similar, from the flat to the top of the dovetail on the lower ring.  Good luck.
Link Posted: 1/25/2009 8:36:47 AM EST
also CAA make a mount for 1" scopes.  i am still trying to find out if it is remountable to 0 though.

http://www.commandarms.com/product.asp?pID=175&cID=22
Link Posted: 1/25/2009 8:55:35 AM EST
I've had good luck with the CAA mount holding zero, but I don't shoot with expensive sub-MOA ammo much, so small shifts aren't very obvious.  Most people, including me, find the included half-circle ring reducers don't work well with 1" scopes, and you have to buy a set of full-circle ring reducers to get good 1" performance.  GG&G makes a good, inexpensive set of ring reducers:
http://www.gggaz.com/index.php?id=233&parents=106

I've got an extensive bench review of the CAA mount here:
www.maxicon.com/guns/optics/caa/caa_dvsr.htm

Here's the Big List of AR15 one-piece mounts, including sections on rings and extended rails:

Big List of AR15 One-Piece Mounts
Link Posted: 1/25/2009 1:07:09 PM EST
Wow - great links!

I like these integrated mounts - they look very sturdy and some are not too expensive.

My problem is that I am setting up to shoot longer range and I am looking at the Burris Signature rings because they seem to have a very good system for offsetting the scope a known amount in the vertical direction so you can have enough vertical adjustment to shoot longer distance.

http://www.burrisoptics.com/sigrings1.html#2

Do any of you have experience with shim these 1-piece mounts to achieve the same effect as the burris rings?
Link Posted: 1/25/2009 7:24:23 PM EST
I don't know of any one-piece mounts that are shimmable.  There are a few with offsets built in, from LaRue, Mamba, Nightforce, Talbot, and Leatherwood, but they tend to be expensive.

One option would be to put the shimmable Burris rings in an appropriate height on a riser or extended rail, going for a total height of 1.4".
Link Posted: 1/26/2009 12:22:46 PM EST
I used standard weaver "high rings" on my LR with a 44 mm scope. Eye relief was not NTCH but I adjusted to it well.

AL
Top Top