I've had quite a few total factory rifles that hold 1 MOA. A 222 Rem and a 308 Win were definitely capable, of fine accuracy.
I have notes on the 308 Win.
20 shots 4, 5 shot groups without letting the barrel cool. 98° windy 15 to 20 mph. 4000 rds on factory barrel Rem 700 police.
Group 1 5 shots .817" 3 .342"
Group 2 5 shots .867" 3 .469"
Group 3 5 shots .725" 3 .332"
Group 4 5 shots .927" 3 .329"
7000 rds on Factory 308 barrel same rifle
4, 3 shot groups.
.364," .187,".105," .303" for an average of .239"
The best groups were 5 shots 1400 yds 7.812"
The best at 1000 yds recorded was 3 shots 1.516" 2 into the same hole, 5 shots 5.148"
I mostly shot 3 shot groups, from the old sniper craft days, never shoot more than 3 shots from one position. I have recorded 9, 3 shot groups average 4.913" at 1000 yards.
Shot chicken eggs at 1000 yds with a factory 700 308 Win Police rifle 26" barrel. 3 hits on one egg group 3 shots .452" 4 shots into .540" and 5 into 1.486" at 1000yds...bullet holes behind the egg. Wrap them in plastic and they take more than one hit, and hit one on the 2nd try... some lucky shots, plus a daisy flower 1 st shot at slightly past 1000, just slightly off center off of a 1/4" thick 3/4" diameter yellow center. Used this rife to dispel alot of information about bullets destabilizing, and transitioning, taking the worst 30 cal bullet shooting at low velocity of 2750 fps, .263 BC going subsonic at 700 to 750 yds shot 3 into 7" and bouncing around a empty 3.5" x 10" tall plastic container, at 1000 yards. 60 MOA drop velocity down to 868 fps and 217 ft/lbs. All done 20 yrs ago with a factory Rem 700 rifle, with factory barrel... the no go would chamber with barely a slight resistance, and the fired case could take a full grain more Varget than the following custom barrels, running 3046 fps in a factory 26" for 8000 rds of accurate shooting, and alot of abuse, barrel cooling was not considered, until the target is obscured by heat waves coming off thr hot barrel...it's a tool, to be used, and discarded.
Then I rebarreled the action several times ...in 308 of coarse, plus a bunch of others..in 308.