Depends on what you mean by "the action has been smoothed." If someone has gone in and "smoothed" the sear surfaces, then you will have to replace parts and/or recut the sear surfaces and reharden them. IF all the internals are stock, trigger pull is affected by hammer main spring strength, trigger spring strength and the sear surfaces themselves. What can or needs to be done depends on the particulars of your gun and there is no way to determine that without seeing it.
What happens a lot is that people go in and "smooth" the sear surfaces or change the angles. HOWEVER, Uberti parts are only surface hardened and in some cases the surface hardening is only .002 or .003 thick. Once you have stoned through the hardening if you do not reharden the stoned area, the trigger pull will go south pretty quick.