Please swap numbers guys, this is a bore 
Why height over bore does not matter
- Thread starter User00040
- Start date
I think you're perspective on how people hunt is a bit myoptic....
I know what you mean but...
Cant is about less than perfect fit/form being high does not affect that. A level, better fit, better form will reduce cant.
Being high will give larger errors on target for the same degree of cant.
Pedantic though.
Yawn...I think people are missing the point of the height over bore video, as related to shooting dynamic (precision) long range. As well as the fact that MDT (who produced the video) is a company that supports primarily, dynamic long range shooting.
Ballistically, it doesn't matter for long range shooters, who typically dial, or holdover (via FFP reticle). Whatever small amount of increase in PBR there is, is totally irrelevant to the long range shooter.
What is relevant is that having a higher mounted scope, allows the shooter to better square up on the rifle and have the buttstock lower in the shoulder, and/or closer to the center line of their body. By doing this the shooter has better recoil management. Which is crucial to modern day long range dynamic engagements (either on steel, or on two legged targets in third world countries). A long range shooter today, equipped with a modern optical scope, and challenged with multiple target engagements, need to see their own impacts so that they can make corrections on the fly, and re-engage a missed target, or quickly engage the next target, using the last target's splash/impact as a wind call adjustment. The days of having a spotter are gone. In today's environment, where danger close is around 600yds, shooters may (and often times do) need to engage as many targets as possible to prevent being overrun before a QRT can respond/form up. Two shooters can put more rounds down range than one, but to do so, they each need to be their own spotter. Hence why today, most long range rigs have the scopes typically mounted higher, so that the shooter can better manage recoil to keep the target in view during recoil. It's the same reason AI and others have begun lowering the rifle actions into the stocks/chassis. Less muzzle flip, and more straight back recoil closer up to the centerline of the torso, with more of the shoulders and upper back squared up behind the rifle (not bladed), and allows them to re-engage the rifle more quickly after recoil. Recoil will always take the path of least resistance. The further away from the center mass of the shooter, the more pronounced the effects of recoil. The more pronounced the recoil, the further the rifle recoils away from the target. And remember, the closer the target gets, the shorter the time of flight, and so, the recoil impulse needs to be shorter to keep the target in view. Tangentially, it's also why we're seeing LOP on rifles getting shorter. Because it's easier to get a shorter LOP closer to centerline, which again, allows better recoil management.
I think many here are taking the video out of context, even if it doesn't really affect even hunting rifles and PBR at typical hunting (stalking) distances. The video was intended for dynamic long range shooters. That being said, it still applies to hunting/stalking rifles as well. I seriously doubt anyone taking an offhand/standing shot is going to be able to shoot the difference of .2".
Ballistically, it doesn't matter for long range shooters, who typically dial, or holdover (via FFP reticle). Whatever small amount of increase in PBR there is, is totally irrelevant to the long range shooter.
What is relevant is that having a higher mounted scope, allows the shooter to better square up on the rifle and have the buttstock lower in the shoulder, and/or closer to the center line of their body. By doing this the shooter has better recoil management. Which is crucial to modern day long range dynamic engagements (either on steel, or on two legged targets in third world countries). A long range shooter today, equipped with a modern optical scope, and challenged with multiple target engagements, need to see their own impacts so that they can make corrections on the fly, and re-engage a missed target, or quickly engage the next target, using the last target's splash/impact as a wind call adjustment. The days of having a spotter are gone. In today's environment, where danger close is around 600yds, shooters may (and often times do) need to engage as many targets as possible to prevent being overrun before a QRT can respond/form up. Two shooters can put more rounds down range than one, but to do so, they each need to be their own spotter. Hence why today, most long range rigs have the scopes typically mounted higher, so that the shooter can better manage recoil to keep the target in view during recoil. It's the same reason AI and others have begun lowering the rifle actions into the stocks/chassis. Less muzzle flip, and more straight back recoil closer up to the centerline of the torso, with more of the shoulders and upper back squared up behind the rifle (not bladed), and allows them to re-engage the rifle more quickly after recoil. Recoil will always take the path of least resistance. The further away from the center mass of the shooter, the more pronounced the effects of recoil. The more pronounced the recoil, the further the rifle recoils away from the target. And remember, the closer the target gets, the shorter the time of flight, and so, the recoil impulse needs to be shorter to keep the target in view. Tangentially, it's also why we're seeing LOP on rifles getting shorter. Because it's easier to get a shorter LOP closer to centerline, which again, allows better recoil management.
I think many here are taking the video out of context, even if it doesn't really affect even hunting rifles and PBR at typical hunting (stalking) distances. The video was intended for dynamic long range shooters. That being said, it still applies to hunting/stalking rifles as well. I seriously doubt anyone taking an offhand/standing shot is going to be able to shoot the difference of .2".
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OK, here is a handwaving example, taken to the extreme, about how cant can affect both horizontal and vertical.
Consider a rifle sighted in correctly at say 200 yards. In my example the scope might be angled so that is is compensating for say 10" of vertical drop from the bore axis, due to gravity. Ignoring the influence of scope optical axis separation from bore axis.
Now cant the rifle by 90 degrees and shoot it "gangsta style"
Simplistically you could now expect the bullets to hit 10" to the side, and 10" low.
Cant it instead by 180 degrees (shoot it upside down), and expect it to shoot 20" low, but horizontally in line.
Consider a rifle sighted in correctly at say 200 yards. In my example the scope might be angled so that is is compensating for say 10" of vertical drop from the bore axis, due to gravity. Ignoring the influence of scope optical axis separation from bore axis.
Now cant the rifle by 90 degrees and shoot it "gangsta style"
Simplistically you could now expect the bullets to hit 10" to the side, and 10" low.
Cant it instead by 180 degrees (shoot it upside down), and expect it to shoot 20" low, but horizontally in line.
Flat earthers also exist . As regards trajectory over line of sight with very low power things like 12 ft lb air it matters on close targets, its why the 8 yard reducer came in to negate the advantage in trajectory curve via high mounted scopes .
The most important thing in a deer rifle is a consistent all position eye alignment in a deer rifle . Craning your hear right up or compressing it down into uncomfortable stance will both effect the accuracy attained.
Nope didn't watch the video either , a person can have what opinion he wants about such matters
The most important thing in a deer rifle is a consistent all position eye alignment in a deer rifle . Craning your hear right up or compressing it down into uncomfortable stance will both effect the accuracy attained.
Nope didn't watch the video either , a person can have what opinion he wants about such matters
MIND THE GAP!
K
K
The Flat Earth Society has members all round the World.
It's not really about height above bore. It's about stock design. A traditional rifle stock is designed such that when your cheek is in the optimum position on the comb your eye is in line with the original open sights. As soon as you raise the line of sight by fitting a scope (even a low one) then you have to raise your head from the most stable position for that type of stock, which is why we fit comb raisers even when using low mounted scopes. With very high scopes on a traditionally styled rifle you're likely to run into issues with parallax and cant, unless you've got a really funny shaped head and neck, or you fit a seriously unsightly comb raiser that'll probably obscure your bolt.
If it's your jaw, rather than your cheek, that's resting on the stock then you only have to clench your teeth slightly - through nervousness or excitement perhaps - to throw your shot right off.
No, I use a neoprene cover instead of caps on my lowest mounted scope.
As with all these things, it’s what suits the individual best.
Find what you’re comfortable with and practice until your arms fall off and then practice some more.
Find what you’re comfortable with and practice until your arms fall off and then practice some more.
Considering how many people cant
mount a scope properly, I would not be surprised if 5° was seen!You can try that out for yourself using ShootersCalculator.com | Ballistic Trajectory Calculator
Adjust "Shooting Angle" for variation from horizontal whilst also trying out different scope heights.
A quick fiddle shows that it does assume that you are zeroing when horizontal, once you start altering the vertical angle away from zero you start shooting high, whether that be uphill or downhill, which is what we expect. it also messes up any MPBR ideas Now I'm not claiming that shooterscalculator is the be all and end all, but I see it as something reasonably credible, for an indication.
E.g. some example:s Firstly with scope height 1", 200 yard zero, otherwise it's default settings.
MPBR is +/- 2" all the way out to a little over 250 yards.
Now change vertical angle to 45 degrees.
Observe, MPBR out to well beyond 300 yards, but it is all above POA, by as much as 3.3" at 150 yards. Pretty much what you would expect.
Then try a scope height of 2.5" instead.
Now you have a MPBR within 1.5" rather than 2.1 over the same distance. The higher mounted scope works better, flattens the curve.
Now with 45 degree shooting angle:
Again, you aren't benefiting from MPBR, it's all above POA, but worst case by 3" at 175 yards rather than 3.3" at 150 yards. Slightly better, but not by very much.
Instead apply the "Rifleman's Rule" of thumb. Shooting uphill or downhill by 45 degrees at say 200 yards horizontal distance is equivalent to a distance of 141 yards on the flat according to that. This is the sort of thing that an "angle cosine indicator" clinometer thingy clamped to your 'scope tube predicts. Better than nothing I suppose
But this more elaborate ballistic calculator suggests that that is a significant under estimation. It's no more than an approximate rule of thumb. It's probably less inaccurate for smaller vertical angles, 45 degrees would be pretty extreme. I think that something like it is baked into my laser rangefinder binos, as are a selection of ballistic curves for typical common chamberings. Pus one that I can customise. Although the binos have a one mile (1760 yards) artificial restriction due to ITAR restriction at the time, the ballistic calculator stops at 500 yards, which is sensible given its limitations.
Fortunately the binos do tell me the actual angle measured by their electronic clinometer as well, rather precisely, so if I was so minded I'd ignore the basic inbuilt ballistic calculator and put into e.g. Strelok for a better idea. Together with the atmospheric conditions (barometer and temperature) taken from my Casio watch) Fine for target shooting or even as a precursor to going long range stalking. Just me, my binos , watch and 'phone.
I confess, I do have a basic wind meter as well, Caldwell, which cost me about £25 some years ago. And have played about with this combination when target shooting out to 900m with good results. Beats asking fellow shooters "how many clicks are you dialling for the 900m compared with when we started at 300m" ? Widely varying answers, none of them individually incorrect.
When stalking I just follow what the binos tell me, I have them simply set to tell me how many inches of hold-over or under, which I then guess whilst shooting with a simple duplex reticle 'scope adjusted for MPBR. Simple.
Sorry, I am not in the class of "needing" a Kestrel with baked in Applied Ballistics and a bluetooth linked laser rangefinder or binos, even a wrist mounted Garmin display to link it all together
Bottom line is that if shooting uphill or downhill your bullet is going to strike higher. Which should come as no surprise. I've only shown this out to 300 yards, but once you stretch things to longer distances everything becomes much more pronounced.)
Except that in the real world bullets do not follow a mathematical parabolic trajectory, because their velocity steadily reduces due to air drag. That would only happen if shooting in a vacuum.how could you tell?
I was also interested in your comment that a higher mounted scope would [effectively] flatten out the curve a little bit...my take was that a lower mounted scope would be tangential to a point on a flatter curved section of the trajectory parabola and thus give you a greater point blank range. The PB range would start and finish closer but should extend over a greater distance than the high mounted scope who's PB range would start and finish further away but actually extend over a shorter distance given the tightening curve of the parabola?
Alan
Ballistic calculators instead solve using numerical methods, and if you play around with one you may soon discover that scope height does have an influence. As I think I demonstrated in my post #37 where I compared scope heights of 0", 1" and 2.5". The higher mounting delivering the largest usable MPBR with the smallest deviation. And that's before starting to finesse the numbers for a specific ammunition and rifle combination.
Long range precision types aren't relying on MPBR for "point and shoot", they know, or measure, the range, and dial in their scopes to suit (and/or use fancy reticles with loads of holdover graduations).
More casual types just twiddle the knobs based on "up a bit, down a bit, left a bit, right a bit" etc. Assuming that they even get the bullets on paper to start. If not shooting on dry dusty land might let them see how far off they are by raising dust. But in the UK that's rarely our environment.
I have walked through Montana gun shops and seen all of 5 degrees of cant on trade-ins.Considering how many people cant
Shooting off hand, to me. requires a scope that is mounted as low as possible. If you want to shoot off a platform, a bench, or any other flat surface, you can probably make due with a high mounted scope. ~Muir
alberta boy
Well-Known Member
Met a guy who shot rabbits on an island, he had the scope mounted on his .22 semi so the reticle was an ' X ' instead of the proper ' + '... asked him why, his reply: 'They're called cross-hairs!'
Most on here would not dream of shooting without their precious bipod or shooting sticks at least!
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