I have skimmed this thread, and so far I haven't seen anybody mention the quality of barrels used on No. 1's over the years. (Have owned No. 1s from the earliest to the latest.)
The first models used Douglas barrels, and tended to shoot very well.
Then Ruger started using cheaper barrels, and some were pretty good, and some were awful. Plus, for some reason many of those had extremely long chamber throats, far longer than SAAMI--which generally didn't help.
In the early 1990s Ruger started hammer-forging their own barrels, which immediately improved accuracy not only in No. 1s, but other Ruger rifles. I have yet to encounter one of those that didn't shoot well, and some VERY well--often right out of the box.
