Have 2, 300wm's one heavy one lite. The lite one all of a sudden became a shotgun, looked at everything changed a few things. Took it out and the first 3 shots at 600 were a max of 3" apart (1/2moa) (jhuskey witness) being pinwheels, with two one on top of each other, the 4 an 5th shots were 2-3 moa away, from the first 3. The barrel is being changed and receiver being trued in it should be home next week. Went to Hardrock to shoot yesterday, took the heavy stick. Very first shot was 3 moa low at 600 but I pressed forward any way. At a grand it took 30 moa to get there, so I'm like WTF is going on here. Riding home thinking, at 0130 this am woke up and knew what all the issues were from, me the asshole who never gets his shit mixed up. I had been shooting the heavy guns load in the lite gun and took a lighter load ( my short range playing load) to the match. Talk about being a dumb ass! Lesson learned stay on top of your shit an always double check what goes with what. The little brain-fart will cost me about a grand before it's over, costly lesson. Still does not answer the reason I placed so poorly with the .308 though, must have been the shooter.