While I have a good load worked up for my 300 Win Mag with the 220 Sierra Matchking I am considering a lighter yet high bc bullet that will give flatter trajectory. As mentioned in my previous post I can only rezero up to 550 yards and still be within the hash marks on my scope. I called Barnes and they told me that their 30 caliber 200 grain X bullet is 1.476" long and that it only needs a 1:10 twist to stabilize (presumably even at 30-’06 velocities). Warren Jensen has told me that a 1:10 is fine for his 180 grain J36 bullet. I do not know how long it is but I imagine it is more than 1.4". I have some of Gerard Schultz's 160 HV bullets on order. I would have ordered the 173 HV but it is 1.496" long and he said that I would need a 1:9 twist. I would really rather use the 173 than the 160 because even though it starts out slower it ends up surpassing the 160 due to its much higher bc (650 versus 515). For example, starting the 160 at 3400 and with a zero of 275 yards: At 700 yds velocity = 2180 fps; energy=1690; drop=65” and drift=27” The 173 at a muzzle velocity of 3270 would have the following figures at 700: Velocity=2300; energy=2040; drop=65”; and drift=22” So clearly the 173 outperforms the 160. Now for the big question- does one really need a 1:9 twist for the 173 HV, especially in light of the fact that the 220 Sierra Matchking (one guy I have talked to is shooting the 240 Sierra Matchking from a 1:10 twist 300 Win Mag without any instability), the 200 Barnes X and the 180 J36 will all stabilize just fine from a 1:10 twist? Any thoughts? Thanks, Rufous.