Before starting to change things -
Open the floorplate and check the center screw, it is just in front of the trigger guard - it should not be more than finger tight, if it is chances are it is binding the action. Having the center screw too tight is common and can cause the issue you are having.
Other issues I can see from the picture include -
The sling (if you are trying to shoot groups with it on the rifle) remove it.
Remove the front and rear sling swivel studs so there is no chance that they are hitting the bags during recoil.
Be sure to have the rear bag far enough away from the pistol grip that it cannot hit the bag during recoil.
Replace that rear bag with something better, shooting off of those is like trying to shoot using a baseball as a rest.
If you have a friend who is a good shot have him shoot the rifle - maybe you are getting a little "flinchy" by the third shot.
Chances are though that doing nothing more than loosening the center screw will fix the issue.
drover
