Once I was done with tweaking it during the earliest days, I never ever had a five-shot group exceed 3/4" at 100 yards. That was with 150-grain Remington Bronze Points and with Sierra 150-, 165- and 180-grain bullets.
(Well, okay, I eventually had a copper buildup and a couple of lousy groups had me do a "real" cleaning, after which everything returned to normal.)
I'll exclude the plinkers, since the 169-grain gas checks weren't all that wondrous.
The rifle is a German-made Weatherby Mark V with a #2 profile 26" barrel. Special option; the regular Mark V was not available in '06. I installed a Canjar trigger, early on.
Having a bench rest in the back yard or on the front porch makes life easier.
I've had the same sort of deal with my little Sako Forester .243 carbine. I bought it the same year as the Wby. Initially, five-inch vertical strings; each shot one inch above the previous. Turned out they'd used a two-piece stock. Barrel bands and such nonsense. (Really pretty, though.) I cut the stock back and sweated off the front sight. Did my shim thing, under my uncle's supervision.
Average, ever since: 85-grain Sierra HPBTs, 3/4". 70-grain Hornady SPs, 5/8". But, only maybe a thousand rounds through it.
Damfino. All this stuff has always seemed real simple, to me. I started out listening to my Uncle Joe, back in 1950, and puzzled out a few things for myself. Just took it all for granted, I guess. I don't figure I'm any sort of guru in all this.