Sierra Bullets came out with their 30 caliber 168-gr. International hollow point boattailed match bullet in 1958 designed for 300 metre free rifle matches. It soon became popular for high power matches in both bolt guns and the M1 Garand for use at 200 through 600 yards. It did well at 1000 yard matches, too, when leaving the barrel at 2800 fps which it did with maximum loads in the .30-06 in proper dimensioned (tight groove diameter; .3078 or smaller) barrels at least 24 inches long.
Along came the M14 with its 22 inch barrel and in 1963, its cartridge was first allowed at the US National Matches. The 172-gr. .3086-in. diameter military match bullet used in M118 ammo did well in the M14 as well as the 7.62MM NATO Garands. A lot of the barrels on these rifles were a bit over sized (.3082 or more) compared to groove diameters needed for best accuracy, but that "fat" military match bullet caused enough chamber pressure to push it out fast enough that it did well in the 1000 yard matches.
When Lake City Arsenal began using Sierra's 168 in their new M852 match ammo, things still went good, often better, when tight. But only through 600 yards. Some M14, M1A commercial and M1 rifles shooting it had barrels enough oversize that the bullet didn't leave fast enough. Those 168's would go transonic at 800 t0 900 yards and become unstable enough to change direction. Elongated holes on paper showed they had done so.
Meanwhile, folks shooting these bullets fast enough through tight barrels had no problem. But that wasn't good enough for most folks and pressure on Lake City Arsenal's engineers convinced them to make a change. They came out with the M118LR round using Sierra's 175-gr. HPMK bullet. These would stay supersonic through 1000 yards...even in loose barrels didn't shoot them very fast.
So, yes, Sierra 168's can be used in a .308 Win. for 1000 yard matches. I've won a few using 7.62 Garands and bolt guns using 168's. Some folks have done the same using M1A's with match-tight 22-inch barrels. All you need to do is shoot them fast enough. But then, that's the rule with any bullet in any caliber for long range matches.
Myth busted.
Along came the M14 with its 22 inch barrel and in 1963, its cartridge was first allowed at the US National Matches. The 172-gr. .3086-in. diameter military match bullet used in M118 ammo did well in the M14 as well as the 7.62MM NATO Garands. A lot of the barrels on these rifles were a bit over sized (.3082 or more) compared to groove diameters needed for best accuracy, but that "fat" military match bullet caused enough chamber pressure to push it out fast enough that it did well in the 1000 yard matches.
When Lake City Arsenal began using Sierra's 168 in their new M852 match ammo, things still went good, often better, when tight. But only through 600 yards. Some M14, M1A commercial and M1 rifles shooting it had barrels enough oversize that the bullet didn't leave fast enough. Those 168's would go transonic at 800 t0 900 yards and become unstable enough to change direction. Elongated holes on paper showed they had done so.
Meanwhile, folks shooting these bullets fast enough through tight barrels had no problem. But that wasn't good enough for most folks and pressure on Lake City Arsenal's engineers convinced them to make a change. They came out with the M118LR round using Sierra's 175-gr. HPMK bullet. These would stay supersonic through 1000 yards...even in loose barrels didn't shoot them very fast.
So, yes, Sierra 168's can be used in a .308 Win. for 1000 yard matches. I've won a few using 7.62 Garands and bolt guns using 168's. Some folks have done the same using M1A's with match-tight 22-inch barrels. All you need to do is shoot them fast enough. But then, that's the rule with any bullet in any caliber for long range matches.
Myth busted.