Which Grainger spring is this reference to? I have one of the 45-70 Henry single shot rifles that would definitely benefit from a lighter trigger pull.
If you have a good hardware store nearby, just remove the factory spring, measure the length, diameter, and wire diameter, then buy some with lighter wire, but as close in the other dimensions as possible. Grainger makes you buy ten springs and with shipping it's going to cost you over $30.
Ignore the small inner spring (put it in your Box-o-Crap).
