Arch, the 147s??? Man give me a break... those are the worst of the worst to start out with. Sorry you started weighing those ones, you at least started at the bottom.
No one is within 0.10 of a grain all the time, but some are better than others.
I've weighed regular win, like PP and they are as close as any other hunting bullet.
FWIW I've shot differing weights of bullets at 600 in many matches doing testing. I've come to the conclusion its easy to clean a highpower target at 600 if you have come up with the load Via Audette test, and the charges are within 0.5 grains, and the bullets within 0.3/4 grains and case weights (in 223) within 2.0 grains. Anything over and the groups can open up too much. Finding hunting bullets within that .3/.4 grains is pretty easy on average.
Jeff
