Part 214300 is the P2000 DA/SA hammer spring. The DA/SA hammer spring is lighter than the LEM hammer spring in the USP and HK45 so I assume it is in the P2000 as well.
But you're already sub-5 pounds. Not sure what you're trying to do here. Only costs ya $10 to try it. $5 for the spring and $5 for HKI to send to you.