So, the factory trigger is adjustable?
I think I know just enough about this to be dangerous...
The answer is, "It might be." While the Ruger No.1 triggers have adjustment screws, I believe at some point Ruger (deliberately) made changes so these screws don't really do anything to adjust engagement or overtravel. Almost for sure they don't adjust "pull".
So, if it is an older No. 1, the adjustment screws
may be functional.
I remember reading that Canjar had a replacement trigger for the No. 1 that replicated the original design, but that these are no longer manufactured. If you want one of these, you have to get lucky at an auction, I guess.
Kepplinger has a very nice (and very expensive) set trigger for the No. 1, so there is a way to improve the trigger, if you really want to.
I don't think there is anything like a Timney or Rifle Basix "drop-in" for the No. 1, however.
There are a few gunsmiths who can work on the Ruger No. 1 trigger and get it to a nice 3 lb. pull with no creep. As it was explained to me, the geometry of the trigger isn't "easy Winchester M70", but it can be done, if you have the experience. This is the route I took, when I had two No. 1's rebuilt.