Throughout the '70s and '80s the service rifle to beat in NRA Highpower competition was the M14/M1A and the bullet that most people fed it was the Sierra 168 HPBT #2200. The "168" served shooters well from 200 to 600 yards and millions of them were loaded by the Lake City ammo plant as a component of M852 match ammunition.
M852 was the standard U.S. military sniper round until the advent of M118LR and its 175-grain BTHP Sierra bullet, which extended the reach of 7.62 NATO precision rifles past 1000 yards. Fired from 22-inch M14 barrels, the 168 has a tendency to go subsonic at around 900 yards.
Civilian competitors who didn't have access to an endless supply of M852 like the military teams rolled their own ammo in LC brass using powders compatible with the M14 gas system like IMR4064, IMR4895 and Hogdon H4895 topped with the 168 at approximately 2550 fps. While the M14 gas system is not as fussy as the long, skinny op rod of the Garand, powder burning rates should be kept close to those listed above to avoid battering the receiver.
As a gunsmith who works on M14-style rifles on a daily basis I do a lot of accuracy testing and chew through a lot of ammo. I don't always have time to load my own, and for the last couple years I have relied on Federal American Eagle #A76251M1A 168-grain OTM ammo for testing M1As and .308 Garands.
This new Federal load appears to be the civilian version of the old military M852, and accuracy is outstanding. I have fired numerous sub-moa groups through rifles I didn't expect to perform at that level and honestly this ammunition makes my rifles look good. The chronograph revealed an average velocity of 2557 fps on a very cold Maine morning.
My only complaint about the American Eagle ammo is that Federal doesn't produce enough of it to go around and it always seems to be in short supply with recent political issues stretching supplies even tighter. Try some of this ammo if you can find it. Although the logo on the box states it is meant for M1As it shoots great in bolt-action rifles also.
American Eagle 168 OTM M1A ammo
American Eagle 168 OTM M1A ammo comes packed in the typical red Federal box complete with a picture of an M1A on the front. Buy it if you can find it.
The 168-grain M852 load
The 168-grain M852 load (top) was eventually replaced with the 175-grain M118LR, which provided supersonic velocity past 1000 yards for sniper use.
M852 military ammo
M852 military ammo could be identified by its knurled brass case, and dominated the high power line through the years when the M14 was the choice.