There's not too many 30 caliber rifles I've shot or owned (including the 308 700 Varmint Special) that didn't respond well to the easy button known as the 175 Sierra SMK. An AR-10 with a White Oak clustered 20 around an inch. The very first time the gun was fired. No brass prep, no runout measured, nothing but a pretty basic load. But it has a lot to do with that particular bullet.
That bullet with about any reasonable powder (Varget, 15, 3031, 4064, 4320) seated to 2.800 runs with boring easy, good groups in every 308 I've used it in. 30/06, 300 Mags too.
Its long so runout is low, its tangent so it isn't as finicky about seating depth or throat geometry, most standard dies seat it straight and Sierra doesn't screw with its design every two years....
