Originally Posted by therewolf
OK, let's say you have standard 4-groove rifling. Wouldn't the barrel also
be inclined to twist CCW, because only one groove and land is facing
up at the end of the barrel.
Well, since a properly crowned barrel would actually have each land and grove releasing the bullet on all sides at the same time, the direction of release should be equal on all sides. This is part of what makes the crown an important component to accuracy. Having the bullet lose contact in one area of the muzzle before another would allow gasses to push the bullet in one direction or allow the bullet to come out of the bullet to be tipped and yaw in it's spin and reduce accuracy.
So, idealy you have a concentric bore with a concentric crown an dall forces on the bullet at the time of release is equal on all sides. So this should not be a factor in muzzle rise.