I agree with the comments discouraging Sierra's 168 HPMK used at the longer ranges. It's boattail design is the problem. Unless one shoots them over 2700 fps out the barrel, they typically go subsonic starting about 800 yards. The military match round that had this bullet replacing their circa 1925 172-gr. FMJBT bullet soon learned its shortcommings at the longer ranges. After replacing it with Sierra's 175 HPMK, the subsonic issue went away.
And Berger's newer heavy 30 caliber bullets are doing well at the longer ranges. I'd not be surprised to see Sierra change the shape of their HPMK's to compete with the Bergers. But the Sierra's will still do very, very well at long range. . . . .when the right one's used.
There are better cartridges for accurate shooting beyond 1000 yards than the .308 Win. While it can be done, one's ability to judge crosswinds beyond that is the biggest factor. One of the newer non-belted 30 caliber magnums holding more powder's a better choice. But with their heavier recoil, they're harder to shoot accurately.
With the .308 Win. in a 26 inch barrel, a 1:11 twist will handle bullets from 175 to 200 grains easily. That's been done over a few decades with the .308. Heavier bullets need faster twists; 1:10 with 220 grain bullets and 1:8 with 240 grain ones.
Last edited by Bart B.; October 1, 2012 at 06:28 AM.