McGowen Barrels

[flatshooter]

Damn, this thread is dead.

[5spd]

I have a Mcgowan in 6mm cal (6x45), but its 1/10" twisted and have put 3 shots into 1.5" at 400 yards more than once with 65gr vmaxes, 95g nosler BT & 85g sierra gameking HP bullets. I would try some sierra gameking HP or SMK HP bullets in your .243.
All these go under an inch at 100yds and mostly about .600" in the 6x45.