can I zero at 100 yards with 40 MOA base with 65 MOA elevation scope?

JQIAN

JQIAN

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I have a vortex diamondback tactical with 65 MOA elevation sitting on top of a 40MOA rail base.
Shooting 22LR at 100 yards, do I still have enough elevation at the scope to zero in?

I am kind of worried about so when I ordered the gun I specifically asked for 20MOA, but they still shipped me a 40MOA base and refused to change it.
So I guess either I order another base like 20MOA, or a bigger scope (NX8 with 90 MOA incoming next week).
 
I would say that you do for 100 yards but your image won't look very good with that particular scope when the elevation is maxed out (will be washed out and lose a lot of resolution). You won't be able to zero at 50 for sure. If you already have a nx8 coming, I wouldn't waste time with the diamonback.
 
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JQIAN said:
I have a vortex diamondback tactical with 65 MOA elevation sitting on top of a 40MOA rail base.
Shooting 22LR at 100 yards, do I still have enough elevation at the scope to zero in?

I am kind of worried about so when I ordered the gun I specifically asked for 20MOA, but they still shipped me a 40MOA base and refused to change it.
So I guess either I order another base like 20MOA, or a bigger scope (NX8 with 90 MOA incoming next week).
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The math says no. 65 MOA divided in half is 32.5, so in theory you will still be 7.5 MOA high at 100 and your scope will be bottomed out of elevation.
 
alberta tactical rifle said:
The math says no. 65 MOA divided in half is 32.5, so in theory you will still be 7.5 MOA high at 100 and your scope will be bottomed out of elevation.
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that's what my math told me initially but I started to doubt it now.
Because 22LR standard velocity around 1200 fps drops about 4-7 inches at 100 yards. So that's about the 6-7 MOA I need initially anway. Besides, the scope is sitting about 2 inch high from the barrel (from the center of the scope to the center of the bore). I guess I might be fine.
I won't know until this weekend when I am heading to the range. I can't wait for my nightforce NX8 to arrive to try this new rifle. NX8 won't have issue for sure because it has 90 MOA
 
Should be no problems. I am zero at 50 yrds with 30 moa rail and 30 moa in the scope rings. I've never had a scope right at middle, factory setting that I mounted onto a 22. No problem with a 20 moa rail and an older VX freedom scope with about that for adjustability, and I always zero at 50 yrds.
 
wallz said:
Should be no problems. I am zero at 50 yrds with 30 moa rail and 30 moa in the scope rings. I've never had a scope right at middle, factory setting that I mounted onto a 22. No problem with a 20 moa rail and an older VX freedom scope with about that for adjustability, and I always zero at 50 yrds.
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Just curious as to the scope used to zero a rimfire at 50 yards with 60 MOA of cant. Its definately not a Diamondback like the op. Math doesnt lie and as ATR suggested the op will be short and bottom out before being able to zero. You obviously have a scope with lots of travel but the op isnt in posession yet of one with that kind of adjustment.
 
A very valid point many wouldnt pick up on. But Im pretty sure some keyboard warrior will enlighten you. I think most just dont get it like 60 moa with a 50 yard zero, Ive owned a lot of different scopes from the bottom to the top and dont know of any I could make this happen. Anyway its nice to see someone that understands and gets it.
 
Consider if the rifle without a scope was in a vise-like fixture and a laser was beamed through the bore. When the vise fixture is adjusted so that the laser strikes a target right in the center at 100 yards, the rifle set at 0 (zero) elevation.

If a .22LR standard velocity round such as SK or Lapua was shot at 0 elevation, the ballistics calculator says the bullet with an MV of 1073 fps will drop about 16.7" by the time it gets to the target at 100 yards. A high velocity .22LR round such as a CCI Mini-Mag 40 grain at 1235 fps would drop about 13.5" under the same circumstances.

It's unknown if a scope that's mechanically centered (in the middle of elevation and windage) provides 0 MOA elevation. (To keep things simple, disregard for the moment the factor of line-of-sight height above the bore.) If it did have 0 elevation, however, a 40 MOA canted rail would raise the POI by 40 MOA.

How much would the scope have to be adjusted to account for the higher POI with the known bullet drop?

For anyone wondering about the amount of drop from a bore with 0 elevation, see the ballistics chart generated by gundata.org below.

 
Longstud said:
Just curious as to the scope used to zero a rimfire at 50 yards with 60 MOA of cant. Its definately not a Diamondback like the op. Math doesnt lie and as ATR suggested the op will be short and bottom out before being able to zero. You obviously have a scope with lots of travel but the op isnt in posession yet of one with that kind of adjustment.
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I am not convinced that canted rails are always in spec, let alone ring inserts. From my experience there seems to be a lot of imprecise parts that when stacked need to be shot on paper to be sure of what the actual cant is. Often users forget that ring spacing makes a big difference too.
 
Longstud said:
Just curious as to the scope used to zero a rimfire at 50 yards with 60 MOA of cant. Its definately not a Diamondback like the op. Math doesnt lie and as ATR suggested the op will be short and bottom out before being able to zero. You obviously have a scope with lots of travel but the op isnt in posession yet of one with that kind of adjustment.
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he said leupold vx-freedom. I checked, most of them are just 60 MOA elevation travel max.
By the way diamondback tactical is not as bad as you think, the quality of glass is pretty acceptable with its price range, especially considering it's 4-24 and 50mm objective lens. I just feel it's kind of "low" to sit on my new rifle, so I beefed it up to nightforce nx8 4-32x50, still in the mail now.
 
emerson said:
I am not convinced that canted rails are always in spec, let alone ring inserts. From my experience there seems to be a lot of imprecise parts that when stacked need to be shot on paper to be sure of what the actual cant is. Often users forget that ring spacing makes a big difference too.
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These are excellent and important points. Rails and inserts may not always be as described. And ring spacing when inserts are used -- whether they are closer together or further apart -- can change the elevation to something else.

To add to these problems, there's no guarantee that bore/receiver alignment is always perfect. Even when a perfectly centered bore occurs, that is the bore is exactly in the middle of the barrel, (and it doesn't occur always), any misalignment of the bore angle with the top of the receiver (i.e. when they aren't perfectly parallel) causes problems that can't be known without shooting on paper.
 
grauhanen said:
These are excellent and important points. Rails and inserts may not always be as described. And ring spacing when inserts are used -- whether they are closer together or further apart -- can change the elevation to something else.

To add to these problems, there's no guarantee that bore/receiver alignment is always perfect. Even when a perfectly centered bore occurs, that is the bore is exactly in the middle of the barrel, (and it doesn't occur always), any misalignment of the bore angle with the top of the receiver (i.e. when they aren't perfectly parallel) causes problems that can't be known without shooting on paper.
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I use a SiteLite bore sight at home, this one: https://www.amazon.ca/SiteLite-SL-100-Mag-Laser-Boresighter/dp/B001NZLJA6
it prints out a sheet paper with recticle and laser beam placement offset depending on the distance you want to zero and sight.
For example I want to zero at 100 yards at range and only have 10 yard at home, so the beam point will be x-inch lower than the haircross.
I found it mostly accurate in terms of elevation, usually only about a few inches off, but the windage is way off sometimes it could be a foot or so.
 
emerson said:
I am not convinced that canted rails are always in spec, let alone ring inserts. From my experience there seems to be a lot of imprecise parts that when stacked need to be shot on paper to be sure of what the actual cant is. Often users forget that ring spacing makes a big difference too.
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I agree with the rings inserts. It amazes me if this thing even works. The shims/inserts can be very finicky and the distance between the 2 rings can change the final angel by a lot.
However the canted rail base is mostly accurate based on my experience.
 
Why not goto the range and try it? Trial and Error is the best source of data vs what data sheets might say.

Like I didn't know my SP01 Shadow needed a shim for the Riton optic I mounted. Till I went to the range and found out I ran out of adjustment.
 
Longstud said:
A very valid point many wouldnt pick up on. But Im pretty sure some keyboard warrior will enlighten you. I think most just dont get it like 60 moa with a 50 yard zero, Ive owned a lot of different scopes from the bottom to the top and dont know of any I could make this happen. Anyway its nice to see someone that understands and gets it.
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This is exactly how I set up all of my rimfires, and have done so for a few other shooters now too.

I can confirm 62MOA and maybe a slight bit more can still be zeroed at close range. 30 MOA rail with ~32MOA of additional cant built into Burris XTR rings. Can zero @ 32m (the lowest point). Have 31.6mrad left to dial - Athlon Ares ETR. Have noticed zero ill-effect on clarity, brightness, or repeatability in dialing turrets.

Anything with around 30mrad of total elevation should work. My son's rifle has a Athlon Helos BTR gen2 4-20 on it, with a total of 29mrad adjustment listed by Athlon. His rifle is built up with somewhere between 55-60MOA of cant between the rings and base, and his rifle is zeroed at 50y. I can dial 30.9 mrad up on the elevation turret still. Again, no noticeable ill-effect on clarity, brightness, or repeatability.

I've been shooting setups like these for around 3 years now (7 or 8 scopes on multiple rifles), and have not seen proof of any claims that people make that zeroing at such extreme ends of the optics elevation travel will have any ill-effect on the scope, image, repeatability, or accuracy. With ammo shooting around 1100FPS, I can dial to just over 500m, and then to around 600 holding the extra 10mrad in the reticle.

Consider yourself Typer Sniper enlightened ;)
 
rlaunay said:
This is exactly how I set up all of my rimfires, and have done so for a few other shooters now too.

I can confirm 62MOA and maybe a slight bit more can still be zeroed at close range. 30 MOA rail with ~32MOA of additional cant built into Burris XTR rings. Can zero @ 32m (the lowest point). Have 31.6mrad left to dial - Athlon Ares ETR. Have noticed zero ill-effect on clarity, brightness, or repeatability in dialing turrets.

Anything with around 30mrad of total elevation should work. My son's rifle has a Athlon Helos BTR gen2 4-20 on it, with a total of 29mrad adjustment listed by Athlon. His rifle is built up with somewhere between 55-60MOA of cant between the rings and base, and his rifle is zeroed at 50y. I can dial 30.9 mrad up on the elevation turret still. Again, no noticeable ill-effect on clarity, brightness, or repeatability.

I've been shooting setups like these for around 3 years now (7 or 8 scopes on multiple rifles), and have not seen proof of any claims that people make that zeroing at such extreme ends of the optics elevation travel will have any ill-effect on the scope, image, repeatability, or accuracy. With ammo shooting around 1100FPS, I can dial to just over 500m, and then to around 600 holding the extra 10mrad in the reticle.

Consider yourself Typer Sniper enlightened ;)
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in my book 30-ish mrad is more than 100 moa. That is certainly fine with 60 moa cant base and zeroed at 50 yards. I am not disputing that.
I have a 90 moa scope incoming as I said but currently only have a 65 moa handy, which I am worried about.
I won't be able to head down to range until the weekend to verify one way or the other
 
JQIAN said:
in my book 30-ish mrad is more than 100 moa. That is certainly fine with 60 moa cant base and zeroed at 50 yards. I am not disputing that.
I have a 90 moa scope incoming as I said but currently only have a 65 moa handy, which I am worried about.
I won't be able to head down to range until the weekend to verify one way or the other
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Understood. In that case, it's very unlikely you'll be able to make it zero, even at 100y..
My reply was in response to Longstud suggesting that 60MOA cant and zeroing at 50y was rare if not impossible.

Cheers
 
Hi - it sounds like you have the rifle coming so I'd say wait until it shows up and give it a try. It will depend on many factors such as how high your scope is, your zero distance and the velocity of your ammo. I believe that there is a good chance that it will work for you with a 50 yards zero and Sub-sonic ammo. I say this because I use to run a Savage B22 with the Vortex BDT 6-24x50. I had a base and rings combination that added about 45MOA of cant in the scope. It left me with just a little over 0.5 mrad of travel below my zero. Bonus, now I essentially had a zero stop!

Cheers,

T.
 
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