This thread included a little discussion about the importance of leveling a rifle for long distance shooting, but that wasn’t its primary focus, so I’m starting one dedicated to the issue as something that may be of interest to some of the membership. (I don’t intend it to be a matter of debate, and therefore I won’t; the facts can speak for themselves.)

I was prompted by this video that does a good job of explaining why rifle cant matters at long distances and even includes a couple of live fire demonstrations of the phenomenon. There have also been more scientific discussions of the matter that can be found by appropriate Internet searches.

In short, however, canting (tilting) the rifle so that the scope sight reticle and center of the bore aren’t in the same vertical line with respect to gravity can cause the bullet to deviate left or right from where it would impact if things were lined up correctly. As I pointed out in the other thread, that won’t necessarily matter in all situations, but as a student of shooting and ballistics it’s something that interests me, and may interest others.

Guns & Ammo TV had a short video on this a few months back and it kind of surprised me that they showed it in that I'd never seen anything on it before.

I was aware of it, though, as I've been a varmint hunter for a long time and discovered the problem for myself.

I recently bought a Kimber Mountain Ascent in .308 with a Swarovski scope for a very reasonable price from a local classifieds. I only looked at it briefly to make sure it hadn't been abused and that the trigger felt okay. The scope was clear but I didn't look at it too closely, as I had determined in advance that Swarovski would honor the warranty.

When I looked at it a few days later to show my brother, I noticed how badly canted the scope had been mounted. I suspect that this may have been a reason for the sale, as the seller had mentioned hunting on pipelines at medium to long range.