Sig P220 recoil spring

[cygnus x-1]

Ok here is my question. I am reloading and want to know if I replace the recoil spring to a lower rating, will my lower grain loads work better? Right now I am loading with unique, 185gr bullet, and 5.0gr of powder. It wants to cycle the gun but just misses the mark a bit. 5.6gr works but is a tad bit strong for my target tastes. Thanks guys.