bigmossyd
First,recoil is a reaction to the bullet being pushed,IE every action has an equal reaction. So the recoil starts when the bullet starts moveing an only in very high speed weapon does it not affect where the bullet hits.
As to holding a gun there are a number of things that can affect group size; to loose or to tight is difficult to repeat and being able to get it the same is critical, there are a lot of people who never get good groups because of that or eye problems. Lee