Math check help on custom moa rings

[Tesoro]

You can cut the rail........

Wanna re-blue it for me?!

 

[Dusty Stevens]

Get a cold shot adjustable base and you can have 300moa at your fingertips

 

[acloco]

Wanna re-blue it for me?!

"Type III black hardcoat anodized" - the picatinny listed in the previous links. A real light spiff of flat black enamel works rather well in such modifications.

 

[Tesoro]

"Type III black hardcoat anodized" - the picatinny listed in the previous links. A real light spiff of flat black enamel works rather well in such modifications.

i'm too ar for that!!! maybe for a mossberg

 

[Ray123]

I have an Anschutz rodent rifle with a vx-2 4-12 AO and elevation turret add on. I have it zeroed for 100 with tac-22 which is my std round. But I would like to shoot it up to to 200 occasionally and play with the dial, holding for wind. I need to order a set of custom moa rings to do this.

The scope has 66 moa adjustment = 33 when reticle centered. For me to dial to 200 I need 19 moa more elevation with the 100yd zero but I bottom out after dialing 9 moa. This tells me my reticle is 24moa down from center at the 100yd zero or 9 moa from the bottom. This is maybe passable as reticle is roughly within 2/3 of adjustment range if I dont touch dial for anymore. 22 moa is 2/3 of total elevation and i'm at 24.

So If I took my rings off and replaced them with 20moa ones and didnt touch scope adjustment, then my 100 yd zero would now be 20 moa too high, If I dialed to get back to 100 yd zero, then the reticle center would be moved 20-24 moa = 4 moa lower than the 33 moa center.

Now with it re-zerod to 100 and then I dial to 200 I will need to lower reticle 19 moa. Reticle will be 19 + 4 moa for total of 24 below center. 2/3 of 33 is 22 so I am just out of the threshold of the 1/3-2/3 rule again.

Due to wind, temp and pressure I could find my self having to add a bit more elevation and be shooting with the reticle pretty far out of adjustment rule of 2/3.

So I figure I would be better off with 30 moa rings instead of the normal 20 moa. 30 moa rings would keep my reticle center safely in the center zone for the 100yd zero and be better positioned for 200 dialing at 14 moa below center.

Does this sound about right 'in theory'?

Burris makes offset shims up to 40 MOA depending on how they are situated...Another fix...
Depends on how far apart your scope rings are.... if they are 4" on center you need .020" shim under the rear scope base...for the 20 moa change at 100 yds...6" center to center you need .033" under the rear base. So take an old one Inch tape measure they are typically. 005" thick. Cut 4 of them for the 4" center to center spacing of the rings... and use your scope bases as a template to drill holes and cut to size then put them under the rear base tighten down re attach scope and shoot for effect...take your tools to the range, incase you think you want to pull one or add one ...so make an extra....the tempered tape measure tape has a natural curve to it.. so it fits round barrels recievers well. Did this on a 308 Win for many thousands of rds and barrel changes...so I could use the whole elevation turrent one turn up from a 100 yd zero to 1400 yds, with the old M3 Mark 4, 3-10 X mil dot. Bottom one click up, for 100 yds zero ...I do it in the dark... all the way up plus one mil dot 1400 yds. Adjust your scope bases to fit your needs...I did most of my target shooting from 800 to 1400 yds 25 yrs ago with the 308, before long range became "a thing", and we were told by the new cartridge developers, "you can't do that with a 308"...most if it has already been done... with a 308.

 

[Tesoro]

Thanks for this shim info. This is my first time 'shimming' for extra moa so good all around learning exercise, from reticle adj limitations to minimum zero and max dial calcs based on load trajectory. And now shim thickness based on ring span. It would be a snap if it were not for a 22lr or a 45-70.

But nothing is ever that straightforward when I try something. My receiver was drilled 4in on center but for talley lightweight offsets to fit my particular scope/eye relief, one of them is flipped which gives me a 3 5/8 in span. And to boot there is a fingernail width clearance between the bell and the barrel! So I wont be able to shim these rings. I will be best off using Burris so I can use the machined in 11mm rail.

And all of this has got me to thinking that with Burris adjustable on rail one will have an extra adjustment opportunity by spacing the rings a bit closer together than standard 4in!! Do you have the formula? Ie .020 is 20 moa at 4in so how many moa if the rings are 3.8 in apart?!

 

[Tesoro]

I got off the line with Burris and they have a 1" rimfire ring that takes inserts and comes with zero cant ones. med or high options ( 420554 for med). This ring set comes with both 3/8 weaver of 11mm euro interchangeable claws. None of this is shown on Burris website thus the confusion.

And then need to order the moa ringset from opticsplanet ( not sold direct or shown on burris website) 626019. Can also just order the 20moa one for 1/3 price but hard to find.

They are on the way.

 

[joshb]

The problem is how to attach them to my rifle. see pic I just posted.

They make an adaptor rail. 3/8” to piccatiny. It can go wider and they’re cheap.

 

[Tesoro]

They make an adaptor rail. 3/8” to piccatiny. It can go wider and they’re cheap.

Right but Burris makes rings that attach to my receiver 11mm rail so no need for a mount. See how they wok out. Thx