All bullets loose quite a bit of accuracy as they slow into the transonic velocity range. mach2.3 to .9 ish, the center of pressure moves forward and yaw of repose, the angle of the axis of the bullet compared to the line of travel, increases and air resistance goes up great ly, slowing and destabilizing it further, boat tail design mitigates this somewhat, with 11-13 degrees being about the ideal, often, bullets literally suddenly tumble out of stability and basically fall to the ground.
Any bullet looses accuracy as it slows into transonic, so high bc/drag coeff bullets at highest velocity reasonable makes for extended range. The venerable 308 is about the minimal cartridge in 30 Cal for much past 1000, and that with heavy bc bullets an long barrels. Bump up another 200+ fps at the muzzle and range steps up a notch too.
Even better these days, is a heavy 6.5 or7mm in a medium large case like the 260/6.5 class, or a bit larger, increases effective range well past the decidedly slow 308 and a185+ bullet. Golly, if one can handle the recoil, a 30/06 and a 200-240 class bullet easily hold above transonic out to around 1500, with legs that can take it to early 2000 before it too, stumbles well into the low transonic, sub Sonic range and accuracy falls off.
Long range target folks seldom use 30s, most use 6.5s, for all the above reasons, plus much lower recoil based shooter effects.
Mil stuff still hangs with the 30, as terminal ballistics matter against other than paper or just ringing a gong.
I still abuse a 308 in my Palma gun as it is required, but my barrel is 32 inches and 1/13 twist, since 155s are the only bullet allowed. 155 @3150 stays above 1900 past 1000, but brass is once and done.
Thanks. This post made clicking on the cheesy blog thread worth it.