Question relates to mounting a scope low to the bore, or using an AR mount on a rail and a high cheekpiece to gain more “up.”
- Thread starter david walter
- Start date
Mount it for comfort and everything else will follow.
-Stan
-Stan
The old school thought of "as low as you can go" is kinda gone. Most will start with 1.5" mount and go from there. This is variable based on the availability of an adjustable cheek piece.
As @stanley_white said, go with what is comfortable.
As @stanley_white said, go with what is comfortable.
^^^ What he said (mount for comfort, in presence of adjustable comb, for long-range applications). The old "axiom" of mounting as close to the bore as possible is irrelevant to the point of comedy in these days of adjustable stocks/chassis and ballistic calculators. I prefer 1.26" rings with my bolt rifles; separate rings as compared to one-piece mounts allow the most options for spacing.
Here is a photo of a long-departed Tikka T3X Varmint with a Vortex Viper PST (30mm tube, 50mm objective) in 1.26" rings. Note the large amount of space between the objective bell and the skinny little barrel - and how low the cheek piece is set. Mounting the scope lower would limit cheek piece adjustability.
Here is a photo of a long-departed Tikka T3X Varmint with a Vortex Viper PST (30mm tube, 50mm objective) in 1.26" rings. Note the large amount of space between the objective bell and the skinny little barrel - and how low the cheek piece is set. Mounting the scope lower would limit cheek piece adjustability.
This is fun.
-Stan
-Stan
Higher is better,
We want our head straight and not rolled over, too low rolls the shooter's head over.
Looks at the door kickers now, they are mounting their optics higher, taller mounts for the win.
I use 1.375" as a minimum now, 90% of stocks have cheek rests that lift, we have plenty of Cheek to use, lower is harder on some chassis today, like the AI ATX, ASR, they are right on the edge of low, so higher is better.
We want our head straight and not rolled over, too low rolls the shooter's head over.
Looks at the door kickers now, they are mounting their optics higher, taller mounts for the win.
I use 1.375" as a minimum now, 90% of stocks have cheek rests that lift, we have plenty of Cheek to use, lower is harder on some chassis today, like the AI ATX, ASR, they are right on the edge of low, so higher is better.
Can confirm what the HMFIC said about the new AT-X, I put my current optic in a set of Area 419 28mm high “medium” rings. Should have gone with the higher rings because the cheek piece is bottomed out to get a cheek weld.
Lesson learned for when I select the permanent optic for that rifle.
Lesson learned for when I select the permanent optic for that rifle.
As a post script to my comment, heading into instructor mode,
We pull every scope and test them in my class; we have seen bent tubes on scopes that are too low as well. The old school, sliding a dollar bill under the bell to show it clears is a bad idea. Too low, the scopes flex and bang the bells and then bend the tubes, they slowly stop tracking correctly. We tested certain scopes multiple times across the years and saw it happen.
We pull every scope and test them in my class; we have seen bent tubes on scopes that are too low as well. The old school, sliding a dollar bill under the bell to show it clears is a bad idea. Too low, the scopes flex and bang the bells and then bend the tubes, they slowly stop tracking correctly. We tested certain scopes multiple times across the years and saw it happen.
Learned that the hard way. Always had my neck cramped then one day it was like a light going on..."Raise the height, dumbass."
It works and really helps you stay on target,
I was in the process of pussying out from buying 1.42" ARC rings for my new scope and this is what I needed to lock in on getting them.
I'm reading your question as whether or not to use a high mount to gain extra elevation adjustment in your scope.
Yes, you would but it'd be inconsequential compared to an angled mount. Go to about the eight minute mark in the MDT video in post #5 where they figure that their 20-inch tall mount extension gives them 3.9 mils of included elevation. If I'm converting it right, that's only about 13.4 moa. With an AR-mount, you'd be at what, ~2.5" height over bore? In simplest terms, that be 1/10th the height of MDT's setup so a gain of only 1.34 moa included elevation.
Also, don't know if you've got an adjustable-height buttpad on your rifle but if you don't, going very tall on the optics mount will put the butt very low in the shoulder.
Most rings and mounts only have about 0.60" difference from their lowest to their tallest rings. Ring height isn't going to position the butt in a spot for most shooters to notice.
And if the rifle is mainly a non prone rifle, lower on the body and closer to the center of the body is better.
Well, maybe it's just me then.
While generally higher is better, IMHO it depends on the rig too...
On an AR or stock/chassis with a similar comb height (like an AI), I go 1.5" for scopes, 1.63 (lower 1/3) for dots, or 1.93" for dots under NV.
Bolt guns, depending on the stock/chassis, are a little different and I wouldn't/don't go as high with something like a Manners/Foundation...
I went from 1.125" to 1.5" on my Manners TCS, and while definitely more "heads up"... with my scope (heavy pig Razor), the 1.5" mount made the rig feel sort of top-heavy/tippy and weird, it didn't settle into a bag as easily, and would track wonky under recoil sometimes for me... I ended up finding that 1.25" was goldilocks for me on that style of rig. YMMV.
1.5" mount
1.25" mount
On an AR or stock/chassis with a similar comb height (like an AI), I go 1.5" for scopes, 1.63 (lower 1/3) for dots, or 1.93" for dots under NV.
Bolt guns, depending on the stock/chassis, are a little different and I wouldn't/don't go as high with something like a Manners/Foundation...
I went from 1.125" to 1.5" on my Manners TCS, and while definitely more "heads up"... with my scope (heavy pig Razor), the 1.5" mount made the rig feel sort of top-heavy/tippy and weird, it didn't settle into a bag as easily, and would track wonky under recoil sometimes for me... I ended up finding that 1.25" was goldilocks for me on that style of rig. YMMV.
1.5" mount
1.25" mount
Frank, et al,
Height above bore?
Height above bore?
I'm not sure what you mean by "up".
If you mean that your head is up more, all sorts of good responses above.
If you mean that you are more able to launch a bullet to some magical ELR distance, that's not how it works at all.
Please clarify.
Your question is very unclear
A 1.5 rings will typically be a 2.5 or something height over bore. Measure each rifle with a caliper (ctr-line of optic to Ctr-line of bolt).
That's the question. I get ring height, but was asking about "at what height over the bore should the center of the scope be?"
Depending on bases and rails, 1.25" - 1.50" yields different height over the bore.
Depending on bases and rails, 1.25" - 1.50" yields different height over the bore.
The answer is: whatever you are comfortable with, and with whatever chassis/stock you have.
So that really doesn't matter.
Make sure the front bell is clear of the barrel and that the scope is high enough that you can cheek weld comfortably. Height over bore is just what ever it ends up being once you are all set up.
Your ballistic app will probably have a place to input that measurement though and it's easy to figure out accurately if you make a few assumptions...the bolt is centered in the bore, the scope center is centered even using the outside of the scope body.
1) Remove the bolt. Use a caliper to measure the diameter. Write that number down. Divide by 2. Write that number down,
2) Measure the scope outside diameter in a place where you can also touch the bolt (once you replace it). Write that number down and divide by 2 and write that number down.
3) Replace the bolt and measure the distance from the top of the bolt to the bottom of the scope (try to use that same spot you measured the scope diameter) Write that number down.
4) Add the final numbers found in 1 and 2 to the number you found in 3. Your result is the height above bore.
The answer is up to your size and form. If you are comfortable at 2.7 or 1.8....that's the answer....with bell clearance obviously.
For height of scope, I take tube dia ÷2 plus the action dia÷2 plus the space between the two.....and it always seems to work on the prediction.
For height of scope, I take tube dia ÷2 plus the action dia÷2 plus the space between the two.....and it always seems to work on the prediction.
Doesn’t matter what your height over bore is, you can account for it in the calculation. Just have to measure it the same as you do on everything.
understood
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