Re: Do you load bipod push or pull.
Look at what LW wrote and think about that. If you create tension with one shoulder over another you push the muzzle off line. The rifle really should feel as though it is merely resting in the shoulder pocket. If you are using a rear bag or your fist, again you are not creating a tension which leads to a push. Square shoulders means equal tension, trigger finger at the 90, and a straight trigger pull......
Good luck
ETA - yes, the rifle does 'slam' into you. However, a solid position means that the shoulders and hips remain square during recoil, b/c they remain square and everything is in line to start with, it is said that the 'shooter rides the gun'. This is what allows for
minimal POA shifts between shots. Conversely, if you allow your shoulder to go slack you allow a deviation off line during recoil, and over time - ESP with a large calibe you will damage your shoulder.
ETA2 - for those advocate pushing forward - how would you shoot from a cradle in a tripod or simply throwing your coat over a log? Here you have nothing to resist the forward pressure.