I took my new 308 Ultra to the range the other day. I borrowed my son's Barska scope just to keep the shots on paper while I broke in the barrel. After 3 shots in the same hole @ 25 yards (only five shots were fired), I felt confident enough to shoot @ 100 yds. The next few shots were grouped but not tight. Then the shots became very random. Some high and right, some on target, some high and centered. The ammo was Lake City, the barrel was cleaned every 10 rounds. I shot 50 rounds in 2.5 hours. I don't beleive that the barrel was hot enough to cause the problem, if it was this is the only gun I own that has. I am pretty sure the scope is the problem. It is used on my son's 223 Rossi and doesn't get knocked around like the 308 Ultra. All my other scopes are Bushnells.
Being this is my first Ultra I am not sure if the barrels have a tendecy to heat-up quickly. I may have a new Bushnell for the gun before too long.