[Rocky Raab]

The 125-gr in a .308 was because of a LIGHT rifle. The gun in question (if we're talking about the same post) is a Browning MicroMedallion. A 5 1/2 pound .308 is gonna belt the bejeezus out of you with a heavier bullet.

Bsterns, the guys at Remmy would tell you that your barrel meets their specifications and there's noting wrong with it. They don't publish their "specifications" so there's no way to argue the point with them.

I'd predict that it's a barrel harmonics thing: the bullet is exiting the muzzle at different times in the barrel's vibration pattern. Slightly different velocity, slightly different powder burn rate or different bullet weight will help.

With 150-grain bullets, I'd try some slightly faster powders. A classic load with the .308 is 43.0 of 3031 (which is max - work up to it). A more modern powder is Benchmark. Right on the side of the jar, Hodgdon recommends 43.0 of it with a 155 match bullet but a 150 will work just as well.

If the 150s don't work out, step up one notch to 165s. Most 308s shoot VERY well with 165-grain bullets. Try up to 42.0 Benchmark, up to 47.0 of W748 or up to 43 of 4895. Oh, and I also second the motion to try Reloder 15. I haven't done enough work with it in my own .308 to have a pet load, but there is a lot of published data.

Finally, keep in mind that bug-hole groups are nice to brag about, but a rifle that shoots 2-inch groups will collect 99.9% of all venison shots taken.

(Edited to correct the max charge of 4895 under a 165 bullet.)