Scope mount height

[Zoomy]

I recently purchased a NightForce NX 8 1-8 scope for my light weight 3 gun build and considering the Geissele scope mount. I like that Geissele number the saddle and caps before line boring the rings  to keep everything as accurate as possible and they have managed to keep the weight under 8 oz. The question is should I get the standard scope mount with the 1.5” centerline height or the high power version that has a 1.34 centerline height.The NX8 scope has a smaller exit pupil so getting a good repeatable cheek weld and my eye centered might be pesky when shooting long range at high magnification. In that situation I would think that the lower mount would help. Conversely at short rangers at 1X and a more heads up style shooting I would probably want the higher scope mount. 

I am relatively new to 3 gun and probably spent money on the wrong equipment already. The scope height is a mystery to me and need some advice.

[Dwbsig]

I don't shoot three gun but I have shot ar's a lot. I try to mount my scopes about the same as what the standard sights would be . If you mount the scope to low you will have put a lot of pressure on your cheek bone to see thur the scope I would go with the high rings if it was me.

[Steve133]

It's all going to come down to the geometry of the stock that you're using and your body mechanics getting into different shooting positions. Don't know if you're a podcast guy, but there's a recent episode of the 3 Gun Show that has a pretty good discussion on this topic:

https://3gunshow.com/2018/04/03/182-long-range-preparation-with-reuben-aleckson/

 

tl;dr - focus on accommodating your head/eye alignment in the least-forgiving position, typically prone. Don't worry too much about getting a "heads-up" alignment while running and gunning on 1x, since the eyebox is going to be more forgiving on 1x anyway. There are a lot of guys who favor an extra-high mount that lets them go more heads-up, but they usually combine that with an adjustable cheekpiece that they can elevate to still get good and repeatable cheek weld in prone.

 

That said... 1.5" isn't all that high, so you'd probably be fine with that. You can still see through an optic that's mounted too high, even with less-than-perfect cheek weld... but if the optic's too low, you can't exactly force your face through the stock to get a good view. Plus, even if you don't have an adjustable cheekpiece on your stock, you can always add just a bit of height with a pad.

 

I know that this isn't what you asked, but a few anecdotal data points: my 3 gun rifle has a Magpul UBR stock, so probably a little thicker/more solid than an M4-style stock, but no cheek risers or anything. I've had no issues with eye alignment using Burris (1.6" centerline height) or Aero Precision (1.5" centerline height). My favorite thus far has been a Warne mount, which has a 1.43" centerline height.

[Zoomy]

2 hours ago, Steve133 said:

It's all going to come down to the geometry of the stock that you're using and your body mechanics getting into different shooting positions. Don't know if you're a podcast guy, but there's a recent episode of the 3 Gun Show that has a pretty good discussion on this topic:

https://3gunshow.com/2018/04/03/182-long-range-preparation-with-reuben-aleckson/

 

tl;dr - focus on accommodating your head/eye alignment in the least-forgiving position, typically prone. Don't worry too much about getting a "heads-up" alignment while running and gunning on 1x, since the eyebox is going to be more forgiving on 1x anyway. There are a lot of guys who favor an extra-high mount that lets them go more heads-up, but they usually combine that with an adjustable cheekpiece that they can elevate to still get good and repeatable cheek weld in prone.

 

That said... 1.5" isn't all that high, so you'd probably be fine with that. You can still see through an optic that's mounted too high, even with less-than-perfect cheek weld... but if the optic's too low, you can't exactly force your face through the stock to get a good view. Plus, even if you don't have an adjustable cheekpiece on your stock, you can always add just a bit of height with a pad.

 

I know that this isn't what you asked, but a few anecdotal data points: my 3 gun rifle has a Magpul UBR stock, so probably a little thicker/more solid than an M4-style stock, but no cheek risers or anything. I've had no issues with eye alignment using Burris (1.6" centerline height) or Aero Precision (1.5" centerline height). My favorite thus far has been a Warne mount, which has a 1.43" centerline height.

Thanks for the advice. I was also looking at the Warne mount. Another question I have is whether a 20 MOA scope mount is necessary for ranges less than 600 yards. I notice that most of the NightForce mounts only come in 20 MOA.Here is the stock that I have.

 

http://www.missionfirsttactical.com/Products/Rifle-Stocks/BMSMIL-Milspec-Stock

[Steve133]

I don't think that a 20 MOA mount would hurt anything, but it's not necessary for a couple of different reasons. First off, the incline on the mount is intended primarily to keep you from running out of elevation adjustment range on your optic when dialing for a range longer than what it was originally zeroed at. You're basically never going to dial elevation on an optic in 3 gun - you'll zero at whatever range you want to zero at (probably either 100 or 200 yards, almost certainly no more than 300), then hold for elevation instead of dialing.

 

Besides that, like you said, you're unlikely to run into anything beyond 600 yards in 3 gun anyway, and even if you did want to dial for elevation at that range, that's probably not far enough beyond your likely zero distance to run out of adjustment range on the optic.

 

Edit: oh, and I've got that same stock on a lightweight rifle build. I'm not an expert or anything, but I'd consider to be pretty typical in terms of cheekpiece height/thickness - not going to support anything unusually-high (which, for the record, I don't think any of the Geissele mounts are), but doesn't require anything super-low, either.

Edited May 9, 2018 by Steve133

[TheStagePlan]

All depends on your stock to me.  

 

In multigun gun for example:  You are about to run a stage with the shotgun, 10 slugs let’s say. You shoulder the shotgun tight in the meat of you shoulder you then dump the shotgun and pick up the rifle and engage some long distance rifle targets. You naturally shoulder the rifle the same as the shotgun when you do this with a standard magpul type stock  for me at least is to low forcing to lower your head into the gun, then you looking through the top of your eye through a narrow Fov of a 8x scope. 

 

What I run is the geissle 2099 Alcoa precision mount with a Swaro 1-8,  it’s higher then the Warne mount however my stock drops so I shoulder it just like I do my shotgun. 

 

 

Edited May 29, 2018 by TheStagePlan

[Zoomy]

I ended up with the same Geissele mount and the NightForce NX8. I have the Mission First stock. Heads up shooting at 1X is fine but going prone at 8X leaves me searching for the reticle. The scope does not have a generous eye box but with practice I seem to be aligning things quicker.

 

[wgj3]

On 5/8/2018 at 7:10 PM, Zoomy said:

Thanks for the advice. I was also looking at the Warne mount. Another question I have is whether a 20 MOA scope mount is necessary for ranges less than 600 yards. I notice that most of the NightForce mounts only come in 20 MOA.Here is the stock that I have.

 

http://www.missionfirsttactical.com/Products/Rifle-Stocks/BMSMIL-Milspec-Stock

Not needed at all!