Scope or rifle tilt effects

[overbore]

Since I just finished mounting a scope and an anti cant device, ACD, to my son's rifle, I found the following data that is most useful to game and target shooters:

"According to the Marine Corps Sniper Manual, compensating for cant/tilt is critical to long range shooting. At 1,000 yards 6 degrees of tilt will move the bullet strike 55 inches from point of aim's impact with no tilt!

Six degrees of tilt at one hundred yards(100) moves the impact 1/2 (0.5) inches."

Here is a chart of tilt effects at 600 yards and 1,000 yards:

600 yds 1,000 yards
Angle of tilt
1 2 3 4 5 6 1 2 3 4 5 6 degrees

Distance from level zero impact in inches

.5 2.3 4.5 6.7 9.0 11.0 9.0 18.0 27.0 37, 47.0 55 in.

No wonder we miss!!

Overbore

 

[overbore]

The delta between what I actually preview and approve of and what is on the actual post is frustrating as the number values are hashed together. Well I tried. Overbore

 

[kcebcj]

I can read it. Thanks for posting. Had no idea canting had that kind of influence.

 

[overbore]

We are here to share with and help each other, Sir. Cordially, Overbore

 

[Ridge Runner]

I can miss just fine not knowing that!
thanx overbore
RR

 

[overbore]

Well,RR , we just threw out another excuse, didn't we or we just found another "thing" to add to our rifle gear. Cordially, O B

 

[woods]

Actually you can cant your rifle with no ill effects as long as you are holding the reticle level. An extreme example would be David Tubbs rifle

After going through a scope rotation and canting problem, I now use and EXD Device EXD ENGINEERING VERTICAL RETICLE INSTRUMENT at Brownells

to align the scope with the bore. If you set your rifle up in a vise and use the EXD that will insure that the rifle is uncanted. Then you rotate your scope to level the crosshairs on some distant object, I use a 4' level on a fence 30 yards away. When you get the crosshairs level and the EXD device level and lock things down then you have a good start.

But you have to transfer that level to the field. Like overbore, I use an anti-cant device, usually one of these

but I also have one of these

which are the best since you can aim and level without losing cheek weld.

After all, 6 degrees of cant sounds like a lot, but it is only 1 minute on the clock face.

 

[Ernie]

Okay, I'll bite, what is the picture you posted last?

 

[woods]

Meant to post a link

Micro-Level Features

Mine is on a 280AI

and the eye relief is reduced to where it will tap my forehead. I would not put it on a heavy recoiler. But it does work and is a pleasure to use.

 

[Mikecr]

A good ole 'ScopeLevel' will work better with high power scopes and recoil. It also does not require a change in cheek weld, or interfere with an ACI mount.

I must correct the position that crosshairs must be plumb. What if your using a dot?
And if using your turrets for elevation adjustments, travel is what needs to be plumb, not the crosshair.
The only time a level crosshair will help is if it's used for holdover.

I use a T2K setup with 7degs of can't, and all my guns are plumb in elevation adjustments throughout scope range. The actual crosshairs may or may not be plumb. I don't know, doesn't matter for me.

Just a different take on it.

 

[woods]

Hey Mike

I guess with a red dot then leveling the dot could be kinda tough.

Been thinking about the scopelevel

It's not as neat and unobstrusive as the anti cant bubble I have been using.

Could you explain or post a link to the T2K setup? I do know that with cranking turrets or holdover reticles shooting with the reticle level is critical.

 

[davewilson]

Mikecr, i do the same thing, but when testing for verticle tracking, instead of the bullets hitting on the verticle line, i have my bullets hitting about 1/2 inch to the left at 25 MOA elevation when testing at 100 yards. this counteracts the spin drift. i'm only 2" left at 600 but much straighter at 800 and beyond.

 

[overbore]

I started my high power shooting with my M-70, iron sights, but had an apature front sight with an integral bubble level ( Freeland). I was fair with it at 1,000 yds. Overbore

 

[preddhunter]

I am new to long range shooting and was wondering what cant is?