I had a Remington 700 308 worked on about 6 months ago.(rebarreled,action trued,stock bedded)When I got the rifle back it shot great. I was able to keep the shots within .5 moa at 100 yards most of the time. At about 700 rounds I have started to have problems. The first 5 shots out of a cold barrel will hold .5 moa. After the first 5 shots the groups open up to about 1.5 inches at 100 yards. This has happened the last 4 times I took the rifle out. I tried match ammo,a different scope,tightened all screws, made sure there was nothing between the barrel and stock. I have the same problem with reloads and match ammo. Iam not sure what is happening, any help is appreciated.