Depends on the point of impact. If the gun shoots high, like most trap guns, a cant for a right hand shooter will move the shot to the left. A cant is usually caused by an ill fitting stock so the shooter uses some of the drop as castoff.
Don't do it. Get your gun fitted to you as soon as possible. Your gun does not fit you if you do this and you will not shoot your best scores until you fix this problem. A Adj. Butt Plate will do the job. Break-em all. Jeff
When I was being taught to shot a rifle (almost 60 years ago), I was told that the reason we put the target right above the front sight is that the recoil causes the rifle to rise a very small amount before the bullet emerges from the muzzle.
I think recoil has the same effect on a shotgun, although the amount of rise is reduced for an unsingle, as compared to a top single. (I have long understood that this reduction in muzzle rise is part of the reason for shooting an unsingle and/or the lower barrel of a O/U.)
Assuming that reasoning is correct (and I think it is), canting the gun will move the POI to a place to the same side of the target as the bead is relative to the muzzle when the gun is canted. I also have been told that this effect is enhanced when I cant a gun with a high rib. This makes sense only if the high rib causes the shooter to cant the gun more than he does when he shoots a regular gun; the actual movement of the muzzle from one side to the other when the gun gets canted is infinitesimal compared to the size of the pattern.
timb99 is correct. I cannot find the post that Neil did but it was very informative.
There is no practical difference between a low rib or high rib gun. A high shooting gun will be affected by canting. If you have the same cant (and you will) on every shot, and the POI is where you want it, why would it matter?
Where is Neal when we need him? There certainly can't be things this important in Europe. I posted a clip from Leo's DVD on the other canting thread that shows him canting the gun and smoking the target. He was not teaching that but was absolutely doing it. Just saying..............
P.S. Here it is again. Go to 3:42 of this clip. Is that a cant or what?
Gentlemen, we have been through this several times. If your gun shoots at the POA at target distance, then canting the gun has no effect as long as you line the beads up the same way. If, as often is the case with a cant, the beads do not line up up the same way, you will shoot to a different POI.
For high shooting guns, there is a noticeable effect. The more you cant, the more noticeable the effect is. Say you have your gun set up for handicap and it shoots 15" high at 40 yards. If you cant the gun 90 degrees to the right, your POI will be 18" to the left and 3" low, instead of 15" high. Lessor angles of right cant are more or less proportional. You will always be more left and lower than the original POI. It takes geometry or trig to calculate the correct POI.