Sambo3006,
First thing I look at on a rifle with a vertical stringing problem is the bolt lug contact evenness. Was the receiver trued and the lugs trued and lapped before barreling? Were the receiver threads trued as well?
If you have a floating lug you will see vertical stringing in the Rem 700 or any other two bolt lug receiver design. Generally, the ligher the load or the lighter the bullets, the better these rifles shoot.
The higher the pressure or heavier the bullet, the more bolt thrust is created and there is more bolt flexing resulting in more vertical stringing then with lighter loads or bullets.
Check the bolt lugs out first.
Also, look in the receiver and make sure the barrel bolt nose recess in the barrel is clean. If there is something in there making contact between the barrel and bolt when locked up you will get accuracy issues as well so make sure this area is clean as well as the bolt nose.
Check your receiver screws and scope base and ring screws. If your using a windage adjustable scope base make sure the rear clamping screws are holding the rear ring securely.
Did you see any difference when shooting starting loads compared to upper end loads. If you did, I would certainly look at the bolt lugs. This should not happen with a properly trued receiver so let us know some details as to the original rifle build process. What was done to the receiver.
A finicky rifle is generally due to issues in the receiver and barrel machining but can also be as simple as something wedged in the bolt nose recess of the barrel.
Let us know,
Kirby Allen(50)