Flyboyjake,
The link is more evidence of core stripping. I don't automatically accept the diagnosis that the puffs of dirt reported are actually due to bullets coming apart. I've had 168-grain SMK's at .308 Win velocities exhibit their transonic dynamic instability issue at about 700 yards and hook off and make puffs of dirt all around a 750-yard popper target, but I know darn well they weren't coming apart at that speed. They were just hooking around the target, which tumbling end-over-end causes. Where in the trajectory they start to turn end-over-end will vary with how much the core was unbalancing the bullet after having slipped over the "speed bumps" where the inside of the jacket mirrors the land impressions.
The thinner the jacket, the more pronounced those speed bumps are, and match bullets typically have thin jackets because thin jacket cups are easier to form with uniform wall thickness than thick ones are. But that also means they don't have as strong a grip on the core as a thick jacket does. The grip is due to spring-back pressure created by swaging the core in with the jacket surrounded by a die. This expands the jacket against the die, but it is more elastic than the lead, so it springs back inward against the core, gripping it. The thicker the jacket is, the stronger its grip.
I suspect the reason some folks are achieving your velocity without core stripping is due to a couple of contributing factors: One influence would be getting the last 50 fps or so from having a 26" barrel instead of a 24" barrel. The speed isn't the problem, it's how high the rotational acceleration gets at the pressure peak. Acceleration near the muzzle is caused by lower gas pressure, so it slower and doesn't appreciably stress the core and jacket relationship further.
The other factor would be use of a slower, more progressive burning powder. For any given muzzle velocity, the slower the powder, the lower the peak pressure and the lower the peak acceleration. Late-barrel acceleration makes up the velocity difference by virtue of the slower powder having a larger total charge that makes more total gas and therefore loses less pressure after the bullet passes the peak pressure location (usually within the first couple of inches of travel down the bore).
So, going to a slower powder is another thing you can try to tame the core stripping with since you seem to have already demonstrated that lower velocity from your current powder doesn't cause the problem.
