Okay, where does "putting a bullet to sleep" belong in here? Or does it at all. I have heard that some bullets take time (distance) to stabilize or go to "sleep". Typically, the conversation revolves around boat tail jacketed bullets.
I have observed loads that group as well or slightly better at 200 yds than at 100. They also outperform in terms of MOA at 300 than 100yds. My 1:9" twist 6mm Rem. with 100gr BTSP's will print 1" 5 shot groups at 100 yds. and 1-1.5" at 200 yds. It will shoot under 3" at 300 yds. (given reasonably calm conditions, would love to test in a windless tunnel) There is a smaller number of groups at the longer distances. Some have explained this by stating it takes time for the bullet to settle down.
I can't seem to wrap my simple mind around this one. I can see that the rifle is shooting smaller MOA groups at the longer distances, but that seems counter intuitive. A difference in rotational axis while in the bore than in the air? Why with boat-tails? How does a bullet become more stable the further downrange it travels? I don't think it can! Yet, I can demonstrate the results.
Practically it makes no difference, it is a hunting rifle and much more accurate than I can shoot under field conditions.
Oh!.....and none of this has to do with transonic cast loads. These gems start at better than 3000fps. and stay supersonic well beyond 500 yds. Damn!