POI changed if....?

WhelanLad

WhelanLad

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Would the POI change If one was to realign a slightly crooked(vertically) mounted scope?

Only way to really tell would be to align an refire, but has anyone done this ??

whattya say CGNers?
 
AWWWW spewin! haha!
Thanks for this insight.

Not sure if im goin to bother with it for now. maybe when i have to resight after a bump or knock i will straighten things out,
Although it does favour a Left hand shooter ;)

Anyone elses scopes not 100% straight up an down?
 
This old can of worms. Some guys will tell you that it doesn't matter if your crosshairs aren't square. They're wrong. If the vertical wire is not plumb then your adjustments will go up and off to the side. If you're dialing up over a great distance then you will end up out laterally when you dial all the way out there.

Do it. You knwo you want to. If you haven't got the discipline to get the scope properly level then...:D
 
Ha, BUM.... I want to only because its anoying me knowing its not plumb....!
But i CBF really an A/ i cant seem to find the allen key B/its windy out to re sight and C/ im out of here for couple weeks tomorow lol!
 
Ahoy.

Put 'er plumb 'n level. Resight'r in. Blow off them rounds.

You know it'll bug you right batty 'till you do.:p

What if you were to be holding over for that 1200 yard 'trophy of a lifetime' shot?.
As it stands ... lateral displacement could be a prob, eh?. :p
 
I can't believe I'm replying to this... But here we go:

If your rifle is vertically "plumb," AND your scope's vertical cross hair is "plumb," AND your scope's optical centerline is in-line with the centerline of the bore, you have only the up-and-down trajectory to consider.

If you installed your scope so that the vertical crosshair is canted sideways in relation to the vertical centerline of the rifle, AND you fire a shot with the vertical crosshair perfectly .. well, vertical, you have now introduced a horizontal variable to the trajectory equation. This changes the POI. How much, depends on the degree of the sideways misalignment, the distance from the optical center of the scope to the centerline of the bore, and the distance from the rifle to your target.

However, if you fire the same rifle when the rifle itself is perfectly vertical (so your crosshairs are "off kilter,") the optical center of the scope actually remains vertically "plumb" with the rifle - and the POI is exactly where you sighted it in....

So, how I see it, the answer is "yes, it CAN, and LIKELY WILL affect the POI." How much, will depend on the angle of misalignment AND how the rifle is held when its fired...

Clear as mud?
 
hey Whelan,
We're 1/2 a world ... and a full hemisphere, apart.
And .... you guys got better beer.
Which way does the water rotate in your drain?.
Gonna grab another brew, mate, and ponder the external ballistics on this conundrum.:p
:cheers:
 
vviking said:
hey Whelan,
We're 1/2 a world ... and a full hemisphere, apart.
And .... you guys got better beer.
Which way does the water rotate in your drain?.
Gonna grab another brew, mate, and ponder the external ballistics on this conundrum.:p
:cheers:
Click to expand...

HAHA!! Few differences between here an there, i been to BC an kinda loved it but need to go back again!
 
TAP375 said:
I can't believe I'm replying to this... But here we go:

If your rifle is vertically "plumb," AND your scope's vertical cross hair is "plumb," AND your scope's optical centerline is in-line with the centerline of the bore, you have only the up-and-down trajectory to consider.

If you installed your scope so that the vertical crosshair is canted sideways in relation to the vertical centerline of the rifle, AND you fire a shot with the vertical crosshair perfectly .. well, vertical, you have now introduced a horizontal variable to the trajectory equation. This changes the POI. How much, depends on the degree of the sideways misalignment, the distance from the optical center of the scope to the centerline of the bore, and the distance from the rifle to your target.

However, if you fire the same rifle when the rifle itself is perfectly vertical (so your crosshairs are "off kilter,") the optical center of the scope actually remains vertically "plumb" with the rifle - and the POI is exactly where you sighted it in....

So, how I see it, the answer is "yes, it CAN, and LIKELY WILL affect the POI." How much, will depend on the angle of misalignment AND how the rifle is held when its fired...

Clear as mud?
Click to expand...

HAHA yep, clear as muddy water :S!

One more question for you an it may sound silly to you, as the OP musta been silly to ya,
If you held ya rifle upside down..... Would the bullet Rise as it does upright, an if held on a 90DEGREE angle, say to the left, will the bullet fly as if upright??
:runaway::50cal:


cheers for your rpelie i do appreciate the time
 
I dont leave home without a perfectly level scope, mega important step for top accuracy or precision if you go for perfects groups... JP.
 
TAP375 said:
I can't believe I'm replying to this... But here we go:

If your rifle is vertically "plumb," AND your scope's vertical cross hair is "plumb," AND your scope's optical centerline is in-line with the centerline of the bore, you have only the up-and-down trajectory to consider.

If you installed your scope so that the vertical crosshair is canted sideways in relation to the vertical centerline of the rifle, AND you fire a shot with the vertical crosshair perfectly .. well, vertical, you have now introduced a horizontal variable to the trajectory equation. This changes the POI. How much, depends on the degree of the sideways misalignment, the distance from the optical center of the scope to the centerline of the bore, and the distance from the rifle to your target.

However, if you fire the same rifle when the rifle itself is perfectly vertical (so your crosshairs are "off kilter,") the optical center of the scope actually remains vertically "plumb" with the rifle - and the POI is exactly where you sighted it in....

So, how I see it, the answer is "yes, it CAN, and LIKELY WILL affect the POI." How much, will depend on the angle of misalignment AND how the rifle is held when its fired...

Clear as mud?
Click to expand...

How much does it actually change the poi? I know i try to align my scope as verticle as possible, but i find just tightening the screws down can twist it a bit and to get it perfectly verticle can take quite a while. If it is just off enough to be just noticable will it make much of a difference at normal ranges (200 yards max)?
 
dand883 said:
If it is just off enough to be just noticable will it make much of a difference at normal ranges (200 yards max)?
Click to expand...

Methinks if you can notice it being unlevel with your eye and without a level device then yes it will effect the POI @ 200 yards. Gravity is a harsh Mistress.
 
The zero can be reestablished when the mounts are loosened, the scope position corrected and the mounts retighted if you first align the scope on a boresighter. Note the position of the reticle relative to the boresighter grid, then loosen the screws necessary to make the correction, then use the windage adjustments in the mounts if applicable and/or the scope adjustments to return to its previous zero after the screws are re-tightened. This technique is more precise with higher magnification, but the zero will have to be confirmed by firing in any case. If the boresighter isn't bumped out of position during the process, it should be very close.
 
WhelanLad said:
HAHA yep, clear as muddy water :S!

One more question for you an it may sound silly to you, as the OP musta been silly to ya,
If you held ya rifle upside down..... Would the bullet Rise as it does upright, an if held on a 90DEGREE angle, say to the left, will the bullet fly as if upright??
:runaway::50cal:


cheers for your rpelie i do appreciate the time
Click to expand...

If the rifle is held upside down, the bore is now an inch and a half above the line of sight, so the bullet drop begins at the muzzle rather than crossing the line of sight at 25-50 yards due to the angle of the scope relative to the bore. However, in addition to the sight offset, the angle of the scope relative to the bore is now tipped in the opposite direction resulting in low POIs at any given range.
 
dand883 said:
... i find just tightening the screws down can twist it a bit and to get it perfectly verticle can take quite a while. If it is just off enough to be just noticable will it make much of a difference at normal ranges (200 yards max)?
Click to expand...

I've noticed that rings with screws on one side only will take several attempts to get the scope's cross hairs true... As to how much difference a slight off-plumb install will make, I suppose not much for hunters at short range shots.

Rifles held sideways and/or upside down? Either case, a slight misalignment of the scope would be the least of my worries...
 
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