What caliber, heavy or sporter barrel, have you bedded the action? It will do squirrely things on you specially from one range session to another and if you change the action screw torque. You can do the dollar bill test but you have to remember the safety and trigger assembly is under there. Other things to look at is, are the action screws centered in the pillars? Take your trigger guard off and see if your getting good contact. Sometimes the pillar is sunk farther then the little web of stock between the pillar and the cut-out for the trigger. I have also found a large splinter between the rear pillar and the trigger guard will make you scratch your head trying to figure out that problem.

Since you have vertical dispersion it may be something like the recoil lug/action bouncing forward during recoil. Check things and then maybe play with your action screw torque. Some guys say 25-35 in/lbs but my 112 likes about 50 in/lbs. DO NOT GO OVER 65 in/lbs