Howdy Santee
Your NMRV, came with a 17#, hammer spring, I use 16# Wolff hammer springs, which is just a scooch lighter , but your gun should be just fine the way it is, the OMRV CAME WITH 23# hammer springs, when they designed the new model Vaquero they made everything right , and a lot closer to the Colt SAA, so all you really need to do when you get a new Vaquero, is clean and reoil,=shoot, they are rugged reliable six shooters...
tEN wOLVES