Why does point of impact change?

[hm2 clark]

Yes my Grendel shoots itty bitty groups but...I want it to hit in the same place every time. If I go to the range today and shoot 1/2 inch groups they may be 1-2 inches from where they hit yesterday. And again changed 1-2 inches tomorrow (but not the same change). The wind temp and huminity are all the same. I know this is commen or all the pictures I see posted would be dead center, but the are always off set a little . So Why?

[YutYut]

In my case its a cheap scope. Ive read that SFP scopes tend to be more prone to a change in POI than FFP scopes.

[fanofflyn]

I'd check the stability of the entire sighting system. Including bases. I was in Zimbabwe once wondering why my impact point was wandering a small amount on my .375 ultramag. I shot a Kudu cleanly at 400 yards, only to notice that after my scope was lying on the ground. It had a shear pin in the ring base, and this had gruadually sheared clean through. If the mounts are good, and you've lapped the rings, I would just change to a different scope to see if that fixes it. Other changes have to do with stability of the barrel float system, is it free floated, or did you change the handguards or other barrel support componenets, or did you clean and replace the muzzle brake, or other similar component

[Mutt]

If it isn't your scope, I would tend to think that each time you get into position to fire your weapon your body isn't in the same exact position. Your check weld cold be different. The way you are holding your handguard. Are you using the same exact sandbag or bipod each time. I think the reason your point of aim may be off each time is because of you. Apperantly, the rifle is doing it's job or your wouldn't be shooting small groups each time.

Just a thought.