All No. 1 Have the Same Action
To the best of my knowledge, all Ruger No. 1s are built with exactly the same action. Some might say, over built. That is why Regan Nonneman can re-barrel and/or re-chamber any No. 1 to any cartridge your little heart desires. Here is a link to his site. Check it out.
Ruger No. 1
He did a job for me. Not changing cartridges, but rather turning my moderately accurate Ruger No. 1A in 222 into a very accurate 1V in 222.
That is to say, he turned this:
Into this:
Now I am considering buying some great looking wood to make a very special stock. Then I will be finished messing with that rifle.
I could just as easily have had the rifle turned into a 1A in 300 Win Mag, if I wanted one. All he would have needed to change would have been the barrel.