Quarterbacks training to throw the football with accuracy and a tight spiral can find it tough.
Quarterback training should show you how to properly grip the football. Easier said than done, especially given the shape of the football and its lumpy laces.
Hand size is not as critical on how to grip the football as are strong hands and fingers. Your training on how to grip the football should include strength development for both the hand and fingers.
How to grip the football begins when the ball is snapped, depending on hand size, have at least the wring finger on the laces. You quarterbacks training on how to grip the football, do not want that ball flush in the hand. The ball is gripped mostly with the fingers. As the ball rests in the palm of the hand you want daylight between the ball and the hand where the thumb and forefinger form the U in which the ball rests.
Smaller hands are more towards the back of the football. The larger hands more towards the middle with the air between the web of that hand and ball. Fingers control the spiral and flight of the ball. Strong fingers and hands are needed for efficient passing. The index finger should rest on top of the ball, however if you are having control issues, move the index finger back towards the point of the ball.