[tahunua001]

my 300 wby mag vanguard(first gen) is sub MOA but only cold bore. the difference between a first shot and quick followup shot is nearly 2 inches vertical string but if you take a shot, let the barrel cool for a while take another shot and let it cool again your groups are less than an inch. the cold bore shots always hit 2 inches high at 100 yards and hot bore always hit dead center. I don't understand it but I think that the barrels on vanguards are just not heavy enough to accommodate the great amount of heat generated by the larger magnum cartridges. they just get too hot, too fast and the groups open up.