Scope elevation maxed out.

[captbligh]

Someone may have already mentioned it, but I didn't see anyone recommend using a one piece base if you need to shim. I've got an old Husqvarna with the FN Mauser action and had to shim for elevation. Got a one piece base, shimmed it and lapped the rings. The rings were aligned nicely and no more bluing then normal came off them to get them nicely squared up.

[dk17hmr]

The first time I hit 1 mile was with a shimmed base. It works but I really dislike it, you HAVE to have a one piece mount otherwise you will bind your scope. I like Picatinny Rail with built in MOA, I have several from 0 to 50 MOA. As already stated you may not get a 100 or 200 yard zero depending on the rifle and your scope. Another plus about Picatinny rails is you can get a good set of quick detach rings and swap your scopes back and forth, it really cuts down on having to buy several high quality scopes.

[Copper75]

+1 on the Burris zee rings!
I have one rifle the even with the offset inserts in the zee rings I still added two layers of 35mm film under the rear base.
In my experience you can add one or two layers of film under the rear base and not crimp the scope. It would be best to lap the rings though. Of course, unless you are using zee rings (the only rings I like to use now) you should lap the rings anyway.
Copper

[Lloyd Smale]

theres the right answer.

First, if the scope has run out of elevation something may be wrong with the match between the receiver and bases/rings. How far are you wanting to shoot? Also, shimming the front base yields less elevation. For more elevation you need to shim the rear base. And, you're right- too much shim (front or rear) can put a bind in the scope. Things I can think of to check: make sure the bases/rings are correct for the model/action/receiver and make sure the scope is not on the fritz. I think Burris makes rings that have elliptical inserts that can adjust for a certain amount of run-out if needed. If you do shim, you can reduce the amount of off-axis "bind" to the scope tube by lapping the rings with a scope lapping rod once the bases/rings are mounted to the receiver.

The only time I've ever had windage problems on a rifle was when the base mounting holes were drilled off-axis to the bore line or receiver center line. The old Leupold/Redfield one piece base system addressed that.

And yes, the suggestion about using a rail is a good one. You can use a stiff rail instead of two piece base- then shim the rear of the rail and still avoid most if not all the off-axis bind.

[EDG]

The only problem with the Signature Burris rings with the offset inserts is that a large percentage of shooters have no clue about how to use them and do not have the math skills to make the calculations.

[imashooter2]

The only problem with the Signature Burris rings with the offset inserts is that a large percentage of shooters have no clue about how to use them and do not have the math skills to make the calculations.

They come with clear directions. If'n you can't do the cypherin' necessary to use the offsets in the Burris rings, you aren't smart enough to be installing a scope on your own.

[HangFireW8]

The same math issue exists with shims. I too like Burris Zee rings but I believe it is the Signature Zee rings that have the inserts. Alone they will solve 2 piece alignment problems but the offset shims are extra $$. This is a complete solution but I dislike adding extra parts to an already fragile system. I'm not saying they are problematic, just that I prefer fewer simpler mount/ring systems on my rifles.

My tactic is to shim one piece mounts as necessary, then once sorted out use the shims as a guide on how much to mill the mount.

HF

[Copper75]

For those of us without a mill, the Burris rings work really well. I've got several sets of them and they are by no means fragile.
One set is on my 300 mag with the offset rings and two pieces of 35mm film under the rear base to get the ups I needed for 1000 yards. (Medium size turret scope)
I swear by them !!
Copper

One more thing I love about them, no more lapping rings !

[wiljen]

Depending on what you want to use it on, there are several companies (EGW comes to mind) that make a 20MOA base that has the correct amount of shim built in for 1000 yard shooting.

[slim1836]

Thanks guys, I learned a lot just from the responses, probably need to give it a rest from here on out, unless of course, there is still vital info to be learned out there.

Thanks for all the help,

Slim

[quilbilly]

If you need to move the elevation up 10" at 100 yards, how much shim do you need on the back ring? This was the first time at the range with a brand new rifle (308) and it already shot a group with 4 of 5 CB's touching at 100. Just 10" low with perfect windage.

[geargnasher]

+1000 on the Burris Signature Zee rings. They are ALL I use anymore, including on bench guns. The offset insert kit for 1" rings is about $15 and has three increments, very handy for long-range setups, subsonic loads, or for barrels that droop or aren't square to the receiver like Marlin barrels can be. I'm not sure if the 30mm rings have offsets available or not.

Gear

[felix]

If your BR gun is not perfectly square everywhere, it ain't a bench gun by definition. The Burris scope system is tops all around, and so are the mounting rails for all kinds of paraphernalia. Maybe one of these days, the BR action makers will make the grooves integral with the product so expensive scopes can be interchanged at will. ... felix

[quilbilly]

I guess I better take a look at what these factory installed mounts look like. I got the rifle as a fun project rifle last week on a whim at Wally World where they had a 20% clearance (couldn't help myself at $240 for a Remington 308 with scope included). It was "right on" with military grade 7.62x51 at my home 40 yard range but wayyy low with cast. I cranked the elevation all the way up with cast and is still 9-10" low at 100 yd but that tight group with 160 gr CB's at 100 made me smile even if low. I did another light load group (less than 30/30 factory velocity) with a jacketed 150's flat point and these were only 6" low but the group was 2". I do have some shim material on hand that is .018" so if I understand this theory, if I put material under the back ring, it will move the boolit up 18" at 100 yards. Do I have this right since this all seem counter intuitive?