Scope Height Question

Bigtee-02

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Apr 7, 2018
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#1
Just mounted my Viper PST on my Bergara BMP with an American Defense mount and it looks really high. It feels good on the cheek but I'm worried its too high. I'm new to long range and want to get the rifle right. Let me know what you think please. The base is a 20 MOA and the mount is 0.

Scope Mounted.jpg
 

Rob01

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#7
That's why AR style mounts aren't used on precision rifles. They set the scope up very high. You will be able to shoot the rifle fine like that if it's comfortable for you but you can use standard rings and mount it lower.
 
Sep 17, 2013
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#10
I don’t understand this scope mount is too high comment. If he was running a tube style chassis (xlr, ax,) it would be the same height over bore and no one would say it was too high.
 

Rob01

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#11
I don’t understand this scope mount is too high comment. If he was running a tube style chassis (xlr, ax,) it would be the same height over bore and no one would say it was too high.
Not so much height over bore issue but comfort behind rifle. Usually rifles which tube styles are set up to run higher in the comb area so there is no issue. He should be ok with that chassis as it probably has an adjustable cheek piece but if he isn't then dropping height would be a good idea. Even with adjustable cheek pieces sometimes it's not comfortable to be that high.
 
Jun 13, 2008
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#12
Being of Service Rifle, I won't swear you cannot shoot well without a good (read: repeatable) cheek weld.

That having been said, it sure is a lot easier if you can fully relax your head onto the cheekpiece of the rifle, and have your eye very close to perfectly aligned with the exit pupil or aperture.

Truly, that is almost the only way to get a SURE reptition of cheek pressure and eye placement behind the rifle, and those are important factors to shooting well.

-Nate
 

Bigtee-02

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#13
I changed the mount on it and went with medium rings. It looks better but check rest is all the way down now and I have to get settled in on it. I'll try to get a picture of the new setup.
 

Dthomas3523

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#14
Except for the points Rob made, can anyone give a reason other than “it looks too high” for him to change?

He’s saying it was more comfortable for his cheek weld when it was high and he has to settle in now with it lower.

Assuming he is utilizing proper fundamentals, it sounds like everyone just got him to go with lower rings for aesthetic reasons. 🙄

Should be able to put the height over bore in his calculator and run with it.

I agree with going with a different set of non vertically split rings, but if that height is what works for you, then get non vertically split rings at a similar height.
 
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Dthomas3523

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#15
I changed the mount on it and went with medium rings. It looks better but check rest is all the way down now and I have to get settled in on it. I'll try to get a picture of the new setup.
Don’t do it for purely aesthetic reasons. If it doesn’t help you fundamentally shoot better, go with a higher setup.
 

PFG

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#16
Assuming he is utilizing proper fundamentals, it sounds like everyone just got him to go with lower rings for aesthetic reasons. 🙄
Agree. Silly reason to change rings.

I went through this on my RPR. Med rings worked and "looked right", but the cheek piece was fully lowered. Higher rings gave me a better cheek weld.
 

Dthomas3523

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#18
What is wrong with an adjustable cheek piece being all the way down to get proper cheek weld and eye alignment?
In and of itself, nothing. But he’s saying that when he had a higher mount and higher cheek piece he was able to get behind it without issue.

Now that it’s all the way down, he has to “settle in.” So, we are no longer in the area of “proper” cheek weld and eye alignment.
 

Rob01

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#19
I would like to hear from the OP what the "settle in" comment actually means. Is he uncomfortable or is it allowing him to get on the cheek piece better or does he need to push his face down? Need some clarification before we can figure if it's a good thing or a bad thing. When we teach students we do sometimes have to raise or lower cheek pieces to get them in a good position so we have to figure if his old position was good to begin with. Lots of this is tough to do over the internet.
 
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Jun 13, 2008
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#20
I would like to hear from the OP what the "settle in" comment actually means. Is he uncomfortable or is it allowing him to get on the cheek piece better or does he need to push his face down? Need some clarification before we can figure if it's a good thing or a bad thing. When we teach students we do sometimes have to raise or lower cheek pieces to get them in a good position so we have to figure if his old position was good to begin with. Lots of this is tough to do over the internet.
Thank you, Rob.

I like to ask the student/OP if his neck muscles are flexed on the front, or the back. Neither one is acceptable, but it is more common for the BACKS of guy's necks to be tired after a long day of prone rifle. This is, of course, usually due to a scope too high/cheekpiece too low. I will say, it is easier to shoot acceptably with too LOW a cheek than it is to try to press down on one to attain alignment.

Because of all these things, we (the Internet) almost always recommend the opposite.

In person, a range buddy can help you incrementally LOWER the cheekpiece---you with your eyes closed in between tries---until your eye is perfectly aligned with the brightest image in the scope at highest magnification, and your head is fully relaxed onto the cheekpiece. This procedure has to be done by trial and error with a KMW or similar clamp-bar setup, but target shooters often use thumb wheel adjusters so that we can do all this WITHOUT a partner, and on-the-fly (positions change a little from day-to-day and per firing point, so fine adjustments are usually required).

-Nate
 
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Bigtee-02

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#24
I can get settled in on this ok, just seems like I have get down on it and move around some. With my Tikka CTR and Bergara HMR it kinda comes natural, I get down on it and I’m set. I know I’m inexperienced and have a lot to learn, just want to do it right the first time.
 

PowellSixO

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May 2, 2018
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#26
Forgive me if I'm wrong, I am a newb here, but isn't there benefits to having the scope as close to the barrel as possible? In my mind, the the higher the scope is from the barrel, the more accuracy issues you'll have at long range when accidentally canting the rifle.
 

Dthomas3523

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#27
Forgive me if I'm wrong, I am a newb here, but isn't there benefits to having the scope as close to the barrel as possible? In my mind, the the higher the scope is from the barrel, the more accuracy issues you'll have at long range when accidentally canting the rifle.
Not enough to matter. Obviously canting the rifle will alter the POI, but it will not be exaggerated enough to matter with the optic higher from the bore.

Not to mention the value of having the proper/faster eye relief outweighs the small amount of extra poi shift from cant.

Kinda the same as people saying moa is more precise than mils. Mathematically, yes.......but we can't hold the rifle precise enough to see the difference in the real world.

A higher optic would magnify the effects of cant on paper, but not enough for us to notice in the real world.
 
Jun 13, 2008
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#28
Kinda the same as people saying moa is more precise than mils. Mathematically, yes.......but we can't hold the rifle precise enough to see the difference in the real world.
I'm gonna be "that guy".

While one could argue that the 'real world' does not include International-style metric target shooting...

...if you've spent much time on the 10m, 50m, and/or 300m rifle targets, you'll know that even 1/4 MOA is not a fine enough sight graduation to center your shots.

1/2 cm clicks on the 50m prone target is score-suicide unless you can hold off by less. The 10-ring is only a little over a centimeter TOTAL. Quarters in that ring only allow about a click either way from center before you start losing 9's. (askmehowIknow)



-Nate
 

Dthomas3523

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#29
I'm gonna be "that guy".

While one could argue that the 'real world' does not include International-style metric target shooting...

...if you've spent much time on the 10m, 50m, and/or 300m rifle targets, you'll know that even 1/4 MOA is not a fine enough sight graduation to center your shots.

1/2 cm clicks on the 50m prone target is score-suicide unless you can hold off by less. The 10-ring is only a little over a centimeter TOTAL. Quarters in that ring only allow about a click either way from center before you start losing 9's. (askmehowIknow)



-Nate
Pretty sure the majority of this forum doesn't take part in that.
 

Dthomas3523

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#31
Totally. It was really just an allegory.

When you use "we", it's a really broad statement. There are "we" on this forum who can hold a helluva lot smaller than a tenth MIL.
Yep, we as in most humans, cannot hold a rifle in a practical/tactical rifle situation(which if I'm not mistaken, is the point of this forum) where the difference between an moa and a mil will matter.
 

PowellSixO

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#33
In my mind, I believe you should control the things you can control when it comes to rifle accuracy. Especially, becuase we as humans are not perfect. One might make the argument that this is just a very small item involved in total accuracy, but when everything is all added up it can equal a lot. I mean that's the reason we bed our rifles, level our scopes, lighten our triggers, and so on and so on. It all adds up. So while scope height might be a small thing, I chock it up as one more thing I can control, so I'm going to control it. Haha.
 
Sep 17, 2013
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#34
In my mind, I believe you should control the things you can control when it comes to rifle accuracy. Especially, becuase we as humans are not perfect. One might make the argument that this is just a very small item involved in total accuracy, but when everything is all added up it can equal a lot. I mean that's the reason we bed our rifles, level our scopes, lighten our triggers, and so on and so on. It all adds up. So while scope height might be a small thing, I chock it up as one more thing I can control, so I'm going to control it. Haha.
That makes sense, but you also need to consider the trade off that having a closest-to-bore scope height requires. Namely that in off-prone positions (seated, kneeling, standing, off barricades) the shooter is often looking at the optic through the top half of their eye, along with a greater degree of neck and upper back tension. A higher scope mount usually allows a much more up-right shooting posture, with the eye centered and relaxed.
 
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Rob01

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#35
You can control it but it can also control you if it's too low and makes you shoot worse as you can't get a good position. If a higher scope height works better than no down side if using the rifle correctly.
 
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PowellSixO

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#36
That makes sense, but you also need to consider the trade off that having a closest-to-bore scope height requires. Namely that in off-prone positions (seated, kneeling, standing, off barricades) the shooter is often looking at the optic through the top half of their eye, along with a greater degree of neck and upper back tension. A higher scope mount usually allows a much more up-right shooting posture, with the eye centered and relaxed.
You can control it but it can also control you if it's too low and makes you shoot worse as you can't get a good position. If a higher scope height works better than no down side if using the rifle correctly.

True true, but that can be controlled through proper stock selection or modification can't it?
 

Rob01

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#37
Not always. Scopes can be mounted down low near barrel and not work at all for a shooter no matter what the stock as most are fine going up but don;t go lower. The old "has to be as close as possible" mind set is just that, old.
 
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#38
True true, but that can be controlled through proper stock selection or modification can't it?
Yes you can but you have to consider what is typically available for adjustment. You can achieve the proper fit using a mix of cheekpiece riser, lop adjustments, scope height and recoil pad height. The last adjustment is often not available in most stocks, even chassis systems. It is also what I believe to be the biggest reason why most are unable to use higher scope mounts: because it would required adjustment in recoil pad height to maintain a proper low contact point with the shoulder pocket for in-line recoil.
 
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spife7980

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#40
I think much of the old close-to-the-barrel-as-possible is also a rule of thumb for general hunting, with the scope way high there is a bigger difference inside of 100 yards. Enough to matter? Not really but many hunters still never go over 100 yards on a shot anyways so that close range stuff is an effect that they could easily observe on pie plates at 50 yards. Go beyond 100 yards and the higher up actually works a bit better with the point blank range but again, most deer arent shot any further than 100 yards so the shorthand became what it is.

1.5" over bore -------------- 2.5" over bore
1526488092369.png 1526488113494.png

They also used 50 yards zeros too a bunch to try and time is right for the 50/200 zero and its a bit flatter with the lower scope height to 200 as well.
1526488551660.png 1526488570686.png

Thats my speculation at least
 
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Racegunnr

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May 15, 2018
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#42
With me, after years of abuse to my body, I've discovered a little taller bipod, little taller rear bag and higher scope mount equals more comfortable on my neck when directly behind the rifle, in prone. guess my back bends easier than my neck anymore. Can't craine my neck back to even see through the optics on my sons rifle these days as low as he has everything.
 

scudzuki

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#43
Like Rob01 has commented, some rifles are designed to use a tall mount, even though use of a tall mount (even with a 56mm or larger objective) will leave a large gap between the barrel and the objective bell.

I have an AIAX which requires a relatively tall (Spuhr 4006, 1.35" high) mount for a 56mm objective to clear the forearm (handguard) with its full length Picatinny rail. The comb (cheekpiece) is at the bottom of its adjustment for me to get a proper cheek weld behind the scope at this height, so I couldn't use a lower mount even if the scope bell were a smaller diameter.
My friend has an AIAT, which has the same stock as my AIAX, with the same comb lower limit. Even though the scope objective bell clears the barrel with at least 1/2" to spare with such a tall mount, he can't use a lower mount as he'd never get his eye pupil aligned with the optical axis of the scope because the comb won't go any lower.

With more scope height over the barrel bore comes greater sensitivity to windage error introduced if the rifle is not shot with the scope bore directly above the barrel bore (rifle canted sideways) when the scope is zeroed and when shooting at a distant target. I run a scope mounted level to decrease the likelihood I'll cant the rifle.

It also looks a little odd when there's a large gap between the scope and barrel, another downside to more scope height.

That said, my 2 LR rifles are the 2013 AX and a 6x47 Lapua in an MPA BA-Lite chassis. I run a Minox ZP5 5-25x56 on both. The scope on my MPA is in Seekins low 34mm rings (.92" high) with the comb on the MPA is at its lower limit, resulting in nearly 1/2" lower scope height than the same scope on the AX. The comb on both rifles are 1-7/8" below the optical axis of the mounted scopes, so I get the same cheek weld on both.

Is it possible for you to lower the comb on your MPA? scope heights AI vs MPA cropped.jpg
 
Last edited:
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Aug 31, 2018
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#44
Like Rob01 has commented, some rifles are designed to use a tall mount, even though use of a tall mount (even with a 56mm or larger objective) will leave a large gap between the barrel and the objective bell.

I have an AIAX which requires a relatively tall (Spuhr 4006, 1.35" high) mount for a 56mm objective to clear the forearm (handguard) with its full length Picatinny rail. The comb (cheekpiece) is at the bottom of its adjustment for me to get a proper cheek weld behind the scope at this height, so I couldn't use a lower mount even if the scope bell were a smaller diameter.
My friend has an AIAT, which has the same stock as my AIAX, with the same comb lower limit. Even though the scope objective bell clears the barrel with at least 1/2" to spare with such a tall mount, he can't use a lower mount as he'd never get his eye pupil aligned with the optical axis of the scope because the comb won't go any lower.

With more scope height over the barrel bore comes greater sensitivity to windage error introduced if the rifle is not shot with the scope bore directly above the barrel bore (rifle canted sideways) when the scope is zeroed and when shooting at a distant target. I run a scope mounted level to decrease the likelihood I'll cant the rifle.

It also looks a little odd when there's a large gap between the scope and barrel, another downside to more scope height.

That said, my 2 LR rifles are the 2013 AX and a 6x47 Lapua in an MPA BA-Lite chassis. I run a Minox ZP5 5-25x56 on both. The scope on my MPA is in Seekins low 34mm rings (.92" high) with the comb on the MPA is at its lower limit, resulting in nearly 1/2" lower scope height than the same scope on the AX. The comb on both rifles are 1-7/8" below the optical axis of the mounted scopes, so I get the same cheek weld on both.

Is it possible for you to lower the comb on your MPA? View attachment 6904738

Nice setup. What len and objective covers do you recommend. I've heard butler creek aren't very durable
 

scudzuki

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#45
Nice setup. What len and objective covers do you recommend. I've heard butler creek aren't very durable
The ZP5 scopes come with Tenebraex covers which are pretty decent.
Until the Aadland covers were introduced, I believe the Tenebraex were the gold standard. They do require screw in adapters, though, so they are not compatible with every scope.
The Aadland covers are the best IMHO, and they are available for most popular scopes these days.
The new Vortex Defenders are pretty good, if one is looking to save a few bucks vs. the Aadland. There are only a few different sizes but their construction makes them adaptable to quite a few scopes.
 
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