Depending on your skills, you could polish the trigger bar where it makes contact with the hammer, and grease the contact points. I wouldn't go lighter than a 19# mainspring, for reliability on a carry or defensive weapon. From what I understand, they have used a heavier than normal mainspring, in those for some reason, as some other members have reported.
The newer ones are shipping with lighter springs. The standard M11 (short) hammer spring does a nice job. That was the only thing I did to mine other than shooting the hell out of it. I've replaced the recoil spring once already.
A forum community dedicated to SIG Sauer Pistols and SIG Sauer Rifles owners and enthusiasts. Come join the discussion about optics, hunting, gunsmithing, styles, reviews, accessories, classifieds, and more!