Rifle Scopes 20 MOA base to a 40 MOA base

[Yerman]

Hey guys, Im taking my 6.5CM out to a mile. According to my Kestrel, I need to dial 23 mils to get out that far. With my current 20 MOA base, zeroed at 100, I have 21 usable Mils on my Razord HD Gen II 4.5-24 so I would need to hold a few more on my reticle.

Now, can you guys help me with my math.

According to Vorex, I have 33 Mils of travel of elevation. If I put a 40 MOA base in there, technically, shouldn't I get about 6 more Mils of usable elevation and still be able to zero at 100? And I'd still have about 6 more mills of elevation in my scope that is not usable? 21 + 6 + 6 = 33 Mils

I can do a holdover, but I like to hold for wind so I'd like to dial all my elevation so my wind holdovers are ligned up on my reticle and not floating below the horizontal line in empty space.

 

[Fursniper]

First of all, you don't actually have 33 mils of usable elevation in your vortex. Yeah, I know the spec Web page says that. I already went through all this with them on the phone months ago when I was deciding on a 50 moa rail. The 33 mils is only valid if you completely remove the turret Rev indicator and a few more internals which would leave a hole in the erector housing, etc. The actual available elevation is 28 mils unless you want to dismantle your scope! They told me they need to change the website specs so it's not so misleading but apparently that hasn't happened yet, but yeah, technically speaking, there IS 33 mils lol. I have a gen II on my 260 as well and a mile isn't a problem with my 20moa rail but a 30 would be better as I would be closer to the scopes optical center. Put a 30 on it, you'll still have a 100 yd zero and a great sight picture at 1 mile. I have the same scope on my 338 lapua improved with a 50 moa rail and still have a 100 yd zero so you'd be golden with a 30 rail (you could do a 40 but I don't think you'd need it for a 6.5).

 

[Yerman]

Great response. Thank you

 

[z28kid]

Check your actual travel instead of relying on the scope specs. My first gen pst had 6 mils over the stated 21, my second gen has 7 mils more than it is supposed to, in fact it has 22.5 mils at 100 yards zero.

 

[Long Range 338]

Somebody correct me if I am mistaken on this but another option would be to zero at another distance - say 300 yards for example and then use the upper part of your reticle to hold for 100 yards. This would give you as much elevation as your turrets would allow and possibly more moa in your base.

 

[Long Range 338]

I ran some quick calcs not really knowing any specifics on Hornady's 4DOF and 550 yards comes up at exactly 3 mils. It also would get you to a mile at 23 mils of adjustment, take it for what its worth. You probably wouldn't want to do this if you are going to use the rig for competition but for recreational shooting it will get you to a mile keeping it all inside the turret adjustments. Of course you would now be using a hold under instead of a hold over but at the closer ranges the wind shouldn't bother you too much anyways.

 

[Yerman]

First of all, you don't actually have 33 mils of usable elevation in your vortex. Yeah, I know the spec Web page says that. I already went through all this with them on the phone months ago when I was deciding on a 50 moa rail. The 33 mils is only valid if you completely remove the turret Rev indicator and a few more internals which would leave a hole in the erector housing, etc. The actual available elevation is 28 mils unless you want to dismantle your scope! They told me they need to change the website specs so it's not so misleading but apparently that hasn't happened yet, but yeah, technically speaking, there IS 33 mils lol. I have a gen II on my 260 as well and a mile isn't a problem with my 20moa rail but a 30 would be better as I would be closer to the scopes optical center. Put a 30 on it, you'll still have a 100 yd zero and a great sight picture at 1 mile. I have the same scope on my 338 lapua improved with a 50 moa rail and still have a 100 yd zero so you'd be golden with a 30 rail (you could do a 40 but I don't think you'd need it for a 6.5).

So if I go with 30 MOA base, I only get 3 more mils so I should be right around 24 mils. That's cutting it pretty close if I need to adjust for extra drop or slower loads for some reason.

Based on on me having 21 mils right now, and a 40 MOA base will give me 6 more, I'm still under the 28 available in the scope. Why not go with a 40 MOA base? Am I calculating wrong?

 

[Yerman]

I ran some quick calcs not really knowing any specifics on Hornady's 4DOF and 550 yards comes up at exactly 3 mils. It also would get you to a mile at 23 mils of adjustment, take it for what its worth. You probably wouldn't want to do this if you are going to use the rig for competition but for recreational shooting it will get you to a mile keeping it all inside the turret adjustments. Of course you would now be using a hold under instead of a hold over but at the closer ranges the wind shouldn't bother you too much anyways.

Thanks for all your insight. Most work I do is within 100-1000 yards. I'd like a 100 zero if possible without a hold under.

 

[Long Range 338]

If your scope has 28 mils of useable adjustment you have 28 mils total. With your reticle centered in the scope you have 14 up and 14 down (theoretically - you need to verify your actual equipment). If you add 30 moa that gives you an additional 8.73 mils on top of the 14 mils from center (total of 22.73). I believe this is what you are asking.......

 

[M47Patton]

I was in the same exact situation earlier this year. I had a chance to take my 260 out to a mile. I had a 20 moa rail and figured I needed at least a 30 moa rail.

I ended up going with Burris signature rings. The supplied inserts can give you an extra 0 to 40 moa in elevation. The exact amount of elevation you end up will depend on how far apart your rings are. I used the right combination of inserts to give me an extra 14 moa which did give me enough to shoot out to a mile. I keep my rifle zeroed at 100 yards and I can dial out to 1 mile. The scope is a Vortex pst gen 2 with an advertised adjustment range of 70 moa. I needed 61 moa to make that mile shot.

 

[TheOE800]

Thanks for all your insight. Most work I do is within 100-1000 yards. I'd like a 100 zero if possible without a hold under.

If most of your work is within 1K, don't worry about the situation where you'll need 22 mils or more of elevation. A 20 MOA base will get you out to 1K on the first turn of any modern turret. The odd situation where you need to shoot out to mile is what your holdover reticle is for.

 

[oneshot.onehit]

Yerman
You will do fine with the 40 moa rail when combined with the Gen II Razor, also just to clear up any hearsay as far as misrepresentation Vortex does state on their site that the Razor Gen II has 28.5 mils of useable adjustment within the 33 mils. We actually set up two 375s with Gen II Razors with 80 moa rails in order to be able to dial and then use the hold over hash marks to aim and hit targets well past 3000 yards in the KO2M event. The 40 moa rail will give you a easy 100 yard zero and then give you good use of your internal travel of 28.5 mils

oneshot

 

[Fursniper]

Yerman
You will do fine with the 40 moa rail when combined with the Gen II Razor, also just to clear up any hearsay as far as misrepresentation Vortex does state on their site that the Razor Gen II has 28.5 mils of useable adjustment within the 33 mils. We actually set up two 375s with Gen II Razors with 80 moa rails in order to be able to dial and then use the hold over hash marks to aim and hit targets well past 3000 yards in the KO2M event. The 40 moa rail will give you a easy 100 yard zero and then give you good use of your internal travel of 28.5 mils

oneshot

Thanks for clearing that up. When I was dealing with Vortex on the phone (about 6 months ago) about their claim of 33 mils, they did not state that, (the 28.5 within the 33) only that the gen II had 33 mils of elevation. They told me then they agreed that that was confusing and that they needed to clarify as much on their Web site. Apparently they have finally done that. And yes, a 40 moa rail would serve the op well but I doubt he'd need that much to simply get to a mile with a 6.5. As I stated, I have a 50 moa rail below my gen II and have no problem with a 100 yd zero and still don't need to hold over for 2500 yd shots. It's a great scope, that's why I have two of them.

 

[Covertnoob5]

I had my gen 2 razor on a 40 moa rail and got 28 mils of elevation with my .308 and 100 yard zero. Go with a 40 moa rail if you want too. Should be no issues at all.


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[Yerman]

Awesome. Thanks guys.