Scope too high?

A

ADClope

New member
A slight backstory:

Had a savage MSR 10 long range 6.5 Creedmoor with a Vortex PST 6-24 50 FFP scope mounted on it with a 20 rail.

Traded that rifle off and bought a Tikka T3X CTR 24" Stainless 6.5.

I missed the bolt gun is the reason for the trade.

Anyhow, I also purchased a Bradley adjustable cheek rest for this rifle as I knew the comb height wasn't going to be enough ahead of time.

My question is, with the Vortex mounted on this rifle, it sit's quite high. Now, granted, I may wind up switching this factory rail, which has no MOA built in, with a 20 moa rail or something in the future, so that will obviously tilt the front down some.

I can get the correct height with the Bradley to where it's comfortable and my alignment looks good down the scope, but the scope still looks like it's sitting high on the rifle. Is there any problem with this that I'm unaware of? I'm wanting to avoid buying new rings if it's not necessary.

I think I've got the Burris Signature XTR's now. Like I said, I can get the right height out of this setup, I simply don't know if the scope riding high on the rifle will cause any issues?

Thanks!
 
As far as I'm concerned, the scope should sit as close to boreline as possible w/o interference between front housing and barrel. Mounting the scope higher exacerbates tilt or having the scope's vertical axis mis-aligned. Simply raising the cheekrest is a "crutch" IMHO.
 
Ideal scope height is where you naturally look through the center of the scope when you open your eye. If you have to raise or lower your head to see through the center then you need a different height mount or rings. Too low and you might have problems with scope hitting barrel or bolt hitting scope. You head should be in a natural position when shooting for best results. Having to lift your head or scrunch down isn't desirable for best results.
 
"...tilt the front down some..." That's not a good thing. Means you automatically will run out of adjustment. Better to not use a 50mm front ocular scope and higher rings.
What it looks like doesn't matter.
Like NoSecondBest says, it should be where you naturally look when you open your eye. And the eye relief should be such that you see the full circle of the sight picture.
 
When I was hunting I had high scope rings that were open so I could see the iron sights.

That had two purposes. If the scope got knocked off I could still hunt.

If I had to deal with a shot in the brush or a bear up close, I had full sight picture with the irons.

Its not a factor for hunting, its more of one for target shooting but depending on the shooting bench I get I wind up with minimal cheek weld and still shoot under 1/2 MOA.

Better as low as you can get but its not got any real world issues unless you are David Tubbs.
 
Guys this is being set up ap as a long range target rifle. Not a hunting rifle. All of the above advice is what I'd recommend if it were a hunting rifle. Shoot it and see if it works for you
 
No big issues with a higher scope mount. It mostly comes down to what is comfortable/what works. The stocks on most traditional hunting rifles are more suited to lower scope mounting (about 1 1/2" above bore). But most MSR scopes sit 2 1/2" or more above the bore and the stocks are suitable for such scope heights. Whatever works for you.
 
T.O.
You arrearantly have no clue about how scope bases work.

The 20MOA base is going to be about 0.040" lower in the front. This allows MORE scope travel at longer distances.

Example,
Say for some reason that your ballistics calculator says you need 46MOA to shoot 600 yards.
Your scope has 70 MOA total travel. 35 MOA up, 35 MOA down.
Obviously your not going to get 46MOA travel from your scope.
But the "free" 20MOA from the base would allow you to put in that 46MOA to the scope.
 
"Guys this is being set up ap as a long range target rifle."

In which case, a solid cheekweld and consistent eye to scope center alignment is even more important.
 
If there is a good cheek weld and mounting the rifle is comfortable and all that, what difference does "how it looks" make? Ease of getting small groups would be my priority. :)
 
The industry standard (if there is one) is 1.5" from center of bore to center of objective lens. With large objective lenses it can sometimes be impossible accomplish this. The next option is to get the objective as close to the top of the barrel as possible but no closer than 1/8".

To do this you can use some modeling clay rolled into balls and placed on the rifle at the anticipated mounting points. Push the scope down in a level manner until the objective is 1/8" off the barrel and then remove it. Carefully remove the clay and measure the thickness of the clay. That is the height of your scope rings.

Once you have that number, go find the rings your want to use. If the manufacturer only lists them as low, medium, high, etc., then send them an email and they will tell you the actual height. Once you have that, order your rings according to the measured height. If you can't get an exact match then select the ones that are higher but closest.
 
As Art Eastman said, if the cheek weld is consistent (when you are on the optical line with the scope rear objective), the rings are OK.
Personally, I would check to see if you have lots of space between the 50mm front objective and the barrel.
It shouldn't be touching but I've seen people with more than 1/4 inch between the scope and the barrel.
A 20 MOA rail shouldn't be a problem. It doesn't slope enough that you can even see the slope without measuring.

If you find that you have to raise your natural cheek weld to get on the center of the image, then the rings are too high, but you may not have a lot of alternatives if you have a bull barrel and the 50mm front objective is close to touching the barrel.

If you don't have a consistent and repeatable cheek weld, then you won't get the accuracy you want out of the rifle, especially if you are target shooting.
 
trajectory

A slightly high scope will play with optimum trajectory a LITTLE bit, ie, effect the geometry of line of bore, line of sight, path of bullet , equation. Accepted practice is to get the scope as low as possible w/o touching.

For known distance shooting, I suppose it's no big deal. For a hunting rifle, I'd want to optimize flat trajectory. As the 6.5CM is touted for its long range trajectory, I would want to go with the flat route and go-low. I also have an aversion to awkward looking rigs, and overly high scope bells are on the list.
 
LineStretcher said:
The industry standard (if there is one) is 1.5" from center of bore to center of objective lens.
Click to expand...
That may be the industry standard for ballistics charts, but it is not easy to get to in real life, especially if your scope has an objective lens bigger than about 40mm.

I suspect the only reason ballistics tables use it is because they always have, and it is just a guess, but I expect that number was chosen back when rifles still had iron sights. 1.5" is a decent compromise between the height of irons and height of scopes.

bamaranger said:
For known distance shooting, I suppose it's no big deal. For a hunting rifle, I'd want to optimize flat trajectory. As the 6.5CM is touted for its long range trajectory, I would want to go with the flat route and go-low. I also have an aversion to awkward looking rigs, and overly high scope bells are on the list.
Click to expand...
Really depends on what you plan on hunting, and what your zero range is.

Because of this:

bamaranger said:
A slightly high scope will play with optimum trajectory a LITTLE bit, ie, effect the geometry of line of bore, line of sight, path of bullet , equation.
Click to expand...
There is a specific reason why you might want a higher scope, Varmint hunting. The higher scope will give you the perception of a flatter trajectory past your zero range. Yes, a lower scope will give you the perception of a flatter trajectory before your zero range.

If most of your shots are past your zero range, then assuming you can get a good cheek weld, a little higher is arguably better.

The bullet trajectory won't change (of course) but the way the trajectory intersects with your scope lone of sight will make it seem a little flatter.

Using my Flattop AR, with my ammo, Sierra 55 Blitzking @ ~3000 FPS, and it's rather ridiculous 3" scope height above the bore. With a 100 Yard zero, it is 2" low at 200 yards, and 10.7" low at 300. If I could somehow get the scope down to 1.5" most ballistics charts seem to default to, with the same 100 yard zero, it is 3.5" low at 200 and 13.7" low at 300.

Probably not enough to matter on a deer rifle at any ethical range, but if you shoot little things at unknown ranges, that "perception" helps.
 
I have mixed feeling's on this . I once thought the lower the better but then I started shooting scoped AR's and the scopes on AR's are generally much higher then my hunting type rifles . I have no problem shooting the rifles either way . I just need to look through the scope comfortably and have it doped correctly and I hit what I'm aiming at ( most of the time ) :rolleyes:;)

So now I don't think it matters really how far my scope is off the bore axis , with in reason . I mean , sure 4" above the bore would still work but that would just look silly .
 
For what it's worth, I read an article about testing the height of the scope and the accuracy influence. It concluded that there's no negative influence on accuracy from the scope being mounted higher than normal.
 
It's not the scope height per se that is the problem for me.
Shooting accurately depends on whether I can maintain a consistent cheek weld or not.
Scope height only determines where my cheek has to be to maintain a consistent cheek weld with my eye on the optical center of the rear objective at the scope's highest power.

With my Les Baer Super Varmint .223 and an A2 stock, I tried a low mount to get the scope close to the barrel. The A2 stock has no drop because it was designed for a carry-handle sight on the M-16. Also AR stocks can't have drop like a bolt action because the recoil tube sticks out into the stock.

I had to change to high rings to be able to get any cheek weld that worked and to let my get my eye level with the scope's focal point.

In bolt actions with a drop right behind the bolt to allow the bolt to clear the stock when you operate it, too deep a drop will cause the opposite problem with high rings. On one stock with a deep drop, I needed high rings to allow the large front objective to clear the barrel but that raised the scope high enough that my cheek was barely able to maintain a good cheek weld. I added a cheek pad to get high enough to use the stock.

It all depends on the rifle, stock design, the scope and how consistent you can hold your set up position.
IMO, there is no single answer to how high the rings should be without considering all the conditions needed to set up consistently.
 
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