whats up BAR ?

Im back to piss and moan. The gun is in a vice. Its not moviing. The only way to get it to group is take the scope out of the picture. See if the rifle will group straight out of the barrel. Yes it does, now look thru the scope and put a mark where the crosshairs are on the target just like in the military. Now fire the rifle again look and see where the crosshairs are now they have moved over 2". Remember the rifle has not been moved neither have the scope adjustments. Now you think the scope must not be secure well it is and the scope shoots great on my weatherby 7 mag. I have since did some sear hing and their are others with this problem at least 2 other cases mine makes 3. Their all the same model rifle diffrent calibers. The reciever is all that's left that can be changing with each shot, which the scope is mounted too. Maybe the smaller calibers are not shifting but I for sure this magnum is. Please don't think I just went and bought my first gun yesterday and it doesn't shoot straight Im not the only one their in fact their were 7 people their really more but with a little sense only 7. Forgive my spelling I'm in a little bit of turbulence this morning not real crazy about small planes.

Smokinfz1, I think you misunderstanding.Lock the gun down where you know it will hit the paper even if its a 4 X 8 sheet dosent matter leave the gun in place and go move the target over or whatever it takes so it hits,use no sights on the gun yet. The rifle groups like I said not perfect,because of some seating in the vice and it being a magnum load.Never use the scope for a reference till after the shots are fired.Now fire the rifle using the scope,make no adjustments.Mark each shot where the crosshairs are on the paper with a pencil not the bullet hole.Remember the gun has never been moved.Before second shot mark where crosshairs are on the paper.Fire again, rifle is still grouping just like before you used the scope,but mark where the crosshairs are on the target with a pencil again.Repeat this again,the pencil marks are not grouping understand. Its hard to explain till you see it done,think of it like this, if you could shoot your rifle from your hip,and put your rifle in the exact location everytime when you fire,would it matter if it had a scope or sights. The bullet has a flight path from where the gun is fired regardless,same exact location same path.Hope I didn't screw it up explaining it,or you will be really lost. This technique is great for suspecting crown or other barrel problems.You have to allow some error like I said due to the gun seating in the vice,but you can tell if their is a problem. I got a guy that wants to try something at the range gonna try and go next week,he thinks the reciever is moving too. Thanks guys,if anybody has any suggestions let me hear'em. I kinda want to know whats going on,could just tade it and move on,but it would leave me wondering and give someone else my problem which I hate to do.