That we refer to it as "
swinging" a shotgun is an unfortunate habit because it raises the image of swinging a ball bat, and that isn't the way to move a shotgun.... especially a typical length SxS that is (usually) "light" in the front compared to other types.
Many people begin their shotgunning career with pumps, autos, or maybe the 28" O/U. These guns are long and have some tangible weight forward.
It's very common with these guns for beginners to get in the habit of performing the "swing" mostly by horsing the gun around with their hands/arms/shoulders. You can watch this at any local Skeet shoot.
Then they pick up a SxS and have a difficult time with it - because with its' lighter-forward nature - it MUST be handled correctly - that is the "swing" needs to come mostly from the body's "
core" muscles (lower back, abs, and pelvic )augmented by legs and footwork and,
very importantly,
it has to be controlled and balanced - not jerky and off-balance like some hacker golfer. The hands and arms (and cheek) are the "
mounting/aiming apparatus", NOT the "
swinging apparatus".
But when people start out and learn that "
horse it around with your arms method" - it takes them a goodly while to UNlearn it - whenever they get around to realizing they
need to unlearn it.
Anyone who has ever missed a clay while having someone helping them shoot Skeet has been told "Ya lifted your head off the stock".
Sometimes the person lifts their head, but really not too often.
If one watches closely, it is often NOT that they lifted their head from the stock but that the gun was pulled away (however slightly) from the cheek because the person shifted in mid-movement from using their core muscles to using their arms/shoulders to move the gun and that immediately makes the gun shoot NOT where the shooter is looking.
One thing an instructor can do to help the student with that is tell them (about 1000 times) to "
Keep your head down".
But a
better thing to tell them is that the pressure of their cheek on the comb of the stock
must be the same all the way through the "swing". That makes them focus on using their hands and arms to control that cheek pressure rather than to flail the gun around - that's what their hands/arms are for, and they can't do both at the same time.