My Ruger No 1. in 45/70 was purchased in 1990, I replaced the trigger I have a 3 LB trigger with minimum take-up and worked up the following load.
300 grain Winchester Jacketed Hollow Point, xx grains of Norma N133, Velocity 2300 FPS, group size .604 inch for three shots at 100 yards.
This is better accuracy than I have gotten with most Ruger Model 77 bolt actions, I and others have our doubts about the tolerances on the M77 in particular they seem to have issues with bolt lug contact to the receiver bearing surfaces. Investment casting an action is not as precise as machined actions from my and other viewpoints.
On average I would say that the No1's are as accurate or more accurate than the Model 77's.
I believe that in the 1980's Ruger was getting their barrels from Shaw, Shaw barrels at this time on the bolt actions I worked on averaged close to 1/2 inch 3 shot groups at 100 yds for 3 shots and this included .308 Norma .338 and 375 H&H and .458 Mags. I don't believe that the barrels were the issue, it lay somewhere else.