I have an unmodified Colt 1991 NRM 5" (540 rounds, zero malfunctions). I shoot full power factory rounds and more sedate reloads, 185-230 grain bullets. With factory springs functioning is OK with all charges, even quite low. Spent cases are good, not bulged; ejection is on the "far" side and many primers have a LITTLE indent, sign perhaps of a little early slide opening. In this forum I read to choose the stronger recoil spring that allows proper cycling, in Brian Enos springs forum I read the opposite, even for general use guns. I'd like to have your counseils about wich spring weight and type (constant or variable) choose. Many thanks to all.