How to aim when rifle is canted at an angle?

[hellbndr23]

No problemo, we all have to air them out occasionally.

[DRT]

It's easy with an offset halo sight. Just when you sight in that sight you hold the gun at the 90* position to sight it in and through the hole. The site will be in line with the opening in the fence this way.. Then when you get to those positions you are ready. If you are shooting a 55 grain bullet the drop should be about 16" low at 300 yards with a 50 yard zero. However any left/right deflection, no matter how minor, will be geometrically magnified at 300. So make sure you have a good square bull shot at 50 if that is the only distance you intend to zero.

[Drycreek3189]

not sure the drop for your rig, but you should know how much it drops at 300yds. The holdover would be that amount at a 10:30 orientation from the typical vertical reticle position, I think.

Either that or I am Zombie deadmeat!

Zombies are no threat at 300 yards. Wait and get 'em close up where you can see the splatter !

[howabouttheiris]

The bullet will drop the same, no matter what angle the gun is rotated.
Figure out where you hit, at 300, with the rifle upright, and then holdover the same amount, with the rifle canted.

This does not work that easily.... it would if your scope and barrel were perfectly parallel. But is it not, such that you have a 0 at a specific distance.

[howabouttheiris]

You are rotating the gun to the right correct?

Yes.. in my drawing the larger circle is the scope (on top at 0 degrees). If you cant the other direction you are still adjusting the same vertical, but the windage changes... so your 'opposite shoulder' is a good rule of thumb.

[howabouttheiris]

<<< MATH WARNING >>>>

Here is another view. (stole from my response to this question on another thread)

WARNING: Like this and the method above that I explained, the affect is based on being setup with the elevation adjusted to put the recital on the target and have the round hit where aimed at that distance with 0 cant.... and then canting. It is not based on 'just shooting from your zero', as that takes more math needing velocity, bc, and scope height I did not mention this above as the 50 yard 0 on an AR is already about equal to a 200ish yard zero as well, as seen on this chart. The 'right shoulder' will still work in that context to get you on paper.

Here is the chart (in inches) of the effect of cant on a typical AR round to show this



Here is the cant chart for my 1000 yard gun.

You can quickly guestimate any angle by looking at this chart and holding off the %s that you see. Just think in "drops" and this works for any distance. 30/35/60/90 are pretty common cants and most people (who are carpenters, pipefitters, metalworkers, etc) probably know them as rules of thumb for making cuts already but don't realize it (root 2 / 2 = 0.707, etc.)

My 30" barrel Savage drops 373" at 1000, so that is the reference.
Each red dot on the arching line moving away from the center is 5 degrees cant. (only 0 and 90 are marked)

elevation point of impact is (COS(RADIANS(cant)) * drop) - drop
windage point of impact is (SIN(RADIANS(cant)) * drop) - windage (where I have it at 0)




Hope this helps.....

[hellbndr23]

Awesome info, thanks.