Re: More TACTI-COOL!
If your rifle is canted at all, the bullet is going to arc away from the target.
When the bullet leaves the barrel, it arcs. The reason for the arc is gravity (obviously). The reason the bullet arrives at the POA is the bullet goes straight up, and then straight down.
If the rifle is canted, this movement has a horizontal vector as well. Gravity will not "correct" this horizontal movement, and the bullet will stray left or right depending on which way the rifle is canted.
Obviously, this has a smaller effect if there is a small degree of cant, and if the target is close. However, I think you would find that even a small degree of cant has a larger effect than you might think.