Unless the receiver's epoxy bedded (conventional or pillar, doesn't matter one darned bit) it doesn't take much difference in fit or stock screw torque to change point of impact. Round receivers (Remington) are more prone to zero changes after unstocking one than rectangular ones (Winchester). Not much difference and most folks may not see the difference. If, when restocking, you put the muzzle on a rug then push down on the stock when you make the last couple of turns on the stock screws, you'll force the receiver back to about where it ends up after firing a few shots. The least amout of zero change happens after doing this.
I've removed epoxy bedded barreled actions from Winchester 70's and M1 Garands many times and there's never been a change in zero when they're both torqued up the same amount. 60 inch-pounds on the Winnie's screws and just clamping in the trigger guard on the Garand (always stored with trigger guard unlocked but in place; it does act as a spring).