Please help. I purchased a new 7mm-08 and I am having problems getting consistent groups. Usually the first shot is 1" at 100 yds. Then it seems to begin to rise about 1" each shot, 5 minutes between shots. I am using 140 gr. Winchester balistic tip ammo. Other times they spread all over the target, but in about a 4" diameter pattern within the red. I have shot about 30 rounds and have not cleaned the barrell. Could it be possible I received a bad barrell ?