Originally Posted by Forte Smitten Wesson

Seeing as it is a police trade-in with an unknown amount of rounds put through it, it would seem prudent to purchase replacement springs for it regardless, so I would happily take your word for it and purchase a factory 18lb or 20lb RSA.

Thanks for the information. I looked into the matter further on my own and what I found is that originally there were two types of RSAs for the M&P Compact 1.0 models, a 15lb spring for both 9mm and .40 pistols marked with blue paint as well as a 17lb spring for .357 SIG marked with a yellow/green paint. However, later in production Smith & Wesson found that the 15lb spring was insufficient for .40cal models and began shipping them with 17lb springs.

It will be interesting to see which my M&P40c arrives with.

That being said, it doesn't appear that Smith & Wesson makes anything heavier than the 17lb RSA, so if I were going to go for an 18lb or 20lb RSA, who would you recommend?