Martin,
I am sorry to take so long getting back to your post. I was distracted (I had a great time) by the Dallas Safari club show this last weekend and have been behind since then.
I think the best thing to do is go back to the range. Take a target that is the same as the one you are shooting at so you can mark where each shot hits in relation to your aiming point. Try to use a standing rest or a set of shooting sticks to help steady your aim. Beshure you don’t rest the rifle agenst anything but your hand, if you do it could change your point of impact.
I agree with what Sinner posted.
Did you get aney load data with your rifle? What make and caliber is it?
Basically if your barrels are shooting high and apart but not crossing the velocity is slow if they are crossing and low they are to fast. You will have to do some experimenting to find the load that shoots best.
I would forget about hot barrel cold barrel and just shoot I dought you will find any difference.

Daryl S,
The regulation is directly tied to barrel time or how long the bullet is in the barrel. The barrels will cross and shoot low when they are to fast. They should shoot high and apart if to slow. This applies when you are close to the right velocity. You can make the barrels cross by being realley slow to.
Bill