Older Ruger #1 had adjustments, two in the trigger shoe adjusting over travel and trigger return spring tension. One internal adjustment screw to set sear engagement. This screw changes the weight of pull to about 24oz.
The Ruger#3 has only the two adjustment in the trigger shoe. Weight adjustments have to be made by honing the sear seat in the hammer.
The newer Rugers#1 don't have the internal screw adjustments, from what I hear.
A good addition to any Ruger #1 or #3 is the Keplinger Single set trigger.
Also I honed the hammer seat on both my rifles #1 and#3 and I am happy with a 24oz trigger.