Originally Posted by Jeff56
The spring on mine seems pretty stiff as it is. And I know it has the right spring in it because I just ordered a new one about 6 months ago. But I have seen heavier springs for them. Some were far heavier than the original. I don't remember the ratings on any of them now but I remember springs that were rated at twice the lbs. as the original.
Save your money on the springs. Go with standard, and you will be groovy. The 45ACP isn't a high pressure round, and your Sig is sprung just fine.
I can't think of a single thing you HAVE to do to upgrade the Sig. Other than Glock, Sig is about the only semiauto I consider "poifect out da box". If you WANT to swap grips...by all means...that's a personal choice, not a "have to". I'd get a set of night sights if it's your primary weapon.
Other than that....enjoy the Sig.