Bases/Rings for Extreme range shooting

[wboggs]

I am looking for info on bases/rings for 2000+ yard shooting. I understand you can have MOA built into the base but there would seem to be a limit before the scope will not lie flat in the front ring and would be damaged. I also understand that some scopes have up to about 120MOA of adjustment. All of the adjustment is not available due to some being used in sighting in. There must be something I am missing. Do the Burris plastic offsets have any place? What is the answer to add a lot of MOA to that of the scope?
Thanks
Bill

 

[SierraCJ5]

Murphy Precision will make a base for you with as much slope as you want. Add a good scope with lots of elevation and you'll have no problem dialing 2000+ yds with the right cartridge. It's not uncommon to have 50+ moa in the base if your optic has 120 moa internal elevation.

http://www.murphyprecision.com/

 

[wboggs]

How does the scope body lie square in the rings with a 50MOA base?

 

[Toolbreaker]

How does the scope body lie square in the rings with a 50MOA base?

The cant in the scope base is between the base and the rifle's action. The top surface of the base is still parallel with the scope main tube and rings. The video linked below shows an extreme example of such a base.

https://www.youtube.com/watch?v=t5m_vBSAFoA

 

[JRS]

The scope base is similar to an open sight. By raising the rear of the base to acquire the additional MOA you desire, you are raising the point of impact. A 40 MOA rail is higher at the rear than the 20 MOA rail. The rail slopes towards the barrel. The scope will follow the slope on the base, and will remain properly seated in the rings. You might have to use higher rings for your scopes objective to clear the barrel.

 

[CB11WYO]

It would seem that if someone desires to have a purpose-built +2000 yd gun then they may have to give up having a "normal" 100, 200, or 300 yd zero. At some point I would think that in order to reach 2000, 3000, 4000 etc... you will at some point be extending so far that your equipment would be incapable of dialing back down to "close" range. You will run out of "down" adjustment, just like you were previously running out of "up" adjustment. This is remedied some by the adjustable bases I've seen recently come to market. Where the base itself can be clicked or adjusted from 0 to ??? MOA.

For instance, I just put canted bases and rings (for the OP, they were the Burris ones with plastic inserts) on a rifle that I previously couldn't adjust to a mile with. Now I can click up to a mile and more but I can't dial down below about 250 or so (no biggie I use a 300 yd "0" ).

Sorry if this was off topic, seemed applicable to the OP's frame of mind.

 

[CB11WYO]

How does the scope body lie square in the rings with a 50MOA base?

The cant in the scope base is between the base and the rifle's action. The top surface of the base is still parallel with the scope main tube and rings. The video linked below shows an extreme example of such a base.

https://www.youtube.com/watch?v=t5m_vBSAFoA

This ^^ , yup.

 

[JRS]

What caliber and cartridge are you contemplating, Bill?

 

[wboggs]

Plan is for a .338 Lapua with 300gr Bergers.
There is some excellent information in the posts above. I understand it now. Thanks. Our members are best.
Bill

 

[rayporter]

you can use Burris rings with the inserts. deliberately mismatch the rings and put a very high ring in the rear and a high in the front. the inserts will center up and not mar the scope. close range will be sacrificed, however.

 

[wboggs]

What is the amount of MOA, assume 6" spacing, you can obtain by mismatching the Burris rings? Can this be
combine with their offset inserts? Bill

 

[rayporter]

calling all math wizards for this.

Burris says that .020 inserts move the scope 20 inches at 100yd. but we dont know the ring spacing.

still based on that info, one inch rings with a difference of .150 inches in height would have 150 inches of movement at 100y and if you add in the inserts you could get 190 inches of come up. in this situation you may be using the inserts to take out elevation.

the 30 mm rings on the XYR series have a lot more since there is a .250 height difference.

 

[dkhunt14]

A forty minute base and a 5.5x22 NXS would get you to 2000 or close. It should put you on the bottom at 100. I can go over 2000 with my Lapua IMP.. and 300 Bergers. If you get NPR reticule you would have additional minutes using the reticule. Matt

 

[jghoghunter]

buy a set of Ivey Rings and all the problems go away. They work great and are repeatable. You may need to give him a call. I did a quick look and I don't see the rings with the 150 moa adjustment in them. He's a nice guy and I'm sure he can help you out.
http://www.iveyshooting.com/