Calculating max moa on rail/mount for a 200yrd zero

[JefFamous]

If this being my first post doesn't give it away, I am extremely new to long range precision shooting. With that said, if i say something foolish, i apologize. Now that that's out of the way..

I recently purchased a Ruger Precision in 6.5. I outfitted that with a 4-12 Nikon mounted with a Warne one piece. Everything was torqued/leveled as best i could determine using wheeler tools and forum/youtube assistance.

Over the course of two days I shot this setup at a 12" gong starting at 200 yards and moving in 200 yard increments until i started to feel half way competent shooting at 1000 yards.

Now my Nikon was certainly capable at this range, but it was less than optimal as the cross hairs covered a good amount of the steel plate i was shooting at, so of course i had to upgrade..

After some amount of consideration, i settles on a Vortex Golden Eagle with ECR reticle.

So i know that the Vortex GE only has 55MOA of vertical adjustment. I also know that my rifle has a 20moa rail. Now my question.. Is there a way to calculate how much moa I can add via mount to get the optic reasonably close to bottomed out without mounting it and calculating from there? I don't have a 30mm mount currently to test with, and as I more than likely will be buying another Warne one piece, I'm hoping to determine what size will be best with minimal trial and error. (shipping/return times)

Sorry if that was a bit long winded, and thanks for any and all help!

 

[phantomskittles]

You could estimate but you have to remember it's just an estimate. Normally on most scopes a flat rail and a 100 yard zero will put you at about midway in the range of travel. Which would be 27.5 moa for your scope. A 200 yard zero would be only a minute or so different. If you had a 20 moa rail you could estimate that you would have roughly 46 moa up. If you wanted to minimize shipping and return times you could go with burris signature rings with inserts which would let you fine tune your cant. With them you could add 5-20 moa or take out 5-20 moa.

 

[Lowlight]

There is no reason to have a zero beyond 100 yards on that rifle or set up, you gain nothing.

Zero at 100 yards and drive on, the scopes you are considering are not great and have limited elevation, the Golden Eagle is an F Class scope hence the 60x magnification. Consider something else for an RPR.

Magnification is not always your friend and it can reduce elevation by design. Get a scope suited to the rifle, the Golden Eagle is not it.

 

[b6graham]

is there a reason you want a 200y zero?

Also, a golden eagle is far from ideal. no reason for that much magnification and spo little turret travel, plus its SFP. we may run 5-25x scope but beyond 15-18x is mostly unnecessary for out to a mile'ish

 

[JefFamous]

I was going for 200y instead of 100 just to gain some elevation on the scope, but as phantom pointed out, the gain is next to nil. Im not considering either scope, both are currently owned. The hopes are for the Vortex GE to replace the Nikon as i mostly plan to shoot at 600+. Additionally i would like to consider getting into PRS matches some day, and thought the GE would be a good investment if i could shape it to fit my application.

 

[b6graham]

I was going for 200y instead of 100 just to gain some elevation on the scope, but as phantom pointed out, the gain is next to nil. Im not considering either scope, both are currently owned. The hopes are for the Vortex GE to replace the Nikon as i mostly plan to shoot at 600+. Additionally i would like to consider getting into PRS matches some day, and thought the GE would be a good investment if i could shape it to fit my application.

the GE is pretty far from a PRS capable scope. not that you couldn't but you'll be on a very small list of people who've used one

at 15x min thats a huge handicap and you really wont ever need to adjust magnification, it might as well be a fixed 15x and learn the subtension holdovers there

Ares ETR, gen 2 razor, cronus btr. all of these are much more capable scopes for someone who plans to shoot PRS matches.

if you're only every want to shoot benchrest/f class then the GE will be great. but thats really all that scope is meant for

 

[Lowlight]

you do not gain elevation by zeroing further out.

 

[phantomskittles]

For a RPR if you don't already have the GE I would look at a gen 2 Razor or ATACR. A lot better scopes unless you are wanting a dedicated F class scope. Lots more travel too. If those are a bit pricier than you are looking to go there are plenty of other good choices in the 1000-1500 range. And as Lowlight said you won't gain any elevation by zeroing farther out. I tried zeroing at 200 when I started but eventually realized a 100 yard zero just makes a lot more sense.

 

[JefFamous]

Only if i had significantly increased how much moa i could add to the mount and be bottomed out, but as phantom pointed out, it wouldnt be worth the ~1mil gain. Thank you all for the insight

 

[rsb]

As LowLite said, you gain nothing with a 200 yard zero, just play with your scope turrents and eventuality you will understand the scope internals move up for a 200 yard zero and you run out of adjustments the same with any zero range. Doing this is a great learning tool. The Burris Signature rings will allow you to go to 30 MOA or more, until your scope objective lens hits the handguard or picatinny rail. The more MOA cant you have the higher the eyepiece will be.

 

[JefFamous]

Hypothetical situation: I zero my scope at 400 yards. Thru the use of available equipment and magic for the sake of argument i add a precise amount of cant to the rail so that the optic is bottomed out (with regards to optical clarity) at 400 yards . I now have the full range of 55moa (give or take within manufacturing standards) to dial said scope up from that 400 yard zero. In this circumstance the moa gain would be the vertical dope between a standard 100, and 400. (aprox 6moa for me, according to my ballistic calculator) The same "gain" in usable turret travel is present between a 100y zero and a 200y zero, albeit to a much smaller degree. Now does that make sense, or am i completely missing something?

Just to clarify, I now know and understand that zeroing at 200 is not worth the trade offs i lose over a 100y zero, just making sure i understand the mechanical physics of it.

Again, thanks for any and all input here, clearly still learning the ins and outs.

 

[rsb]

NO. You used magic. And you moved the internal elevations adjustments inside the scope to where it is no longer in the middle of the top and bottom of elevations towards the bottom. You now have 300 yards less of elevations left.

 

[Maxduty]

In other words, in order to do what you want, you'll need a much higher MOA base and rings, but you'll lose all elevation decreases below 200. You'll also put your zero in an area of deficient optical clarity. There is a scope out there that does what you want. I ran across a scop that has crosshairs in the top third of the tube. Similar to this.

Or this one.

But these depend on hold overs, not actually dialing your elevation.