Yeah, if I would have stopped after the 3rd shot it would have been under 1/2" group at 100 yards!
I've noticed that with the slow powders the receiver and first part of the barrel rarely get hot. The hottest area is farther down the barrel. You've probably noticed that the stock grabs the first few inches of barrel, and heat in the area seems to raise the bullet impact. I know that factory 180gr ammo recoils faster and heats the receiver more. I can only guess that its due to the faster powder, but I don't know for sure. I could only shoot 2-3 shots and wait for a cooldown with factory 180gr in my other 300 Win & 300 WSM. And it did seem to take forever.
With my 200gr loads I can shoot 3-5 no problem. I usually take 2 shots, then attach my barrel cooler which is simply one of those battery powered air mattress inflators. I also think the fluted barrel is helping more than I thought it would. Even without my make-shift barrel cooler, the rifle cools down pretty quick.
One other thing that I noticed is that Ramshot Magnum powder is extremely clean burning. No smoked necks, no residue in barrel or at the crown. I'm simply thrilled with it after trying Retumbo and H1000.