Weight of the gun and stock fit/shape could be the difference. Also, 1 1/4 oz out of a 20 will be a 3” load and they generally kick pretty good out of a light 20ga.
Yes, a gas gun will have less felt recoil, but the difference won’t be very noticeable.
Yes, a gas gun will have less felt recoil, but the difference won’t be very noticeable.