Re: 6.5 A MAX New and Old
Several issues are in play that the bullet companies can not control, so they error on the fast side of what actually is needed for twist rate.
1) All barrels are not created equal, cut rifled barrels tend to be more accurate on the helix. A button rifled helix can vary significantly just from one lot of steel being slightly harder or softer than the last.
2) A bullet that will not stabilize in a 12 twist .223, may easily stabilize in a 22/250. Keep in mind twist rate does not stabilize a bullet, RPM will in relation to a couple of other things. The faster you shoot the more RPM the bullet is spinning.
A bullet company wanting to avoid problems will pick the slowest cartridge they think the bullet will be popular in, and then choose a slightly faster twist rate to compensate for Barrel differences across a range of manufacturers.
I shoot the 140 Amax out of a one in nine twist LILJA Barrel, and out of a one in eight twist LILJA with no problems. Anyone who sells you a one in eight twist that will not stabilize this bullet perhaps needs to look hard at how they measure the twist rate of their barrels. You will find very little difference in the RPM necessary to stabilize either design, the old or the new. [img]images/icons/smile.gif[/img]