It’s not like we didn’t already have a whole thread on the topic…
https://pistol-forum.com/showthread....ws-You-Can-Use
But the Cliff notes:
The FN 509 has the best factory modular optics mounting system. That’s not based solely on Cowan’s opinion.
The FN 509 has passed other agency testing (including my own) but simply did not get the contract in those instances. It’s a quality gun. This from someone who would not recommend any prior FN polymer service pistol for any serious use. Simply put when the MHS solicitation came up FN finally got serious about service pistols and they unfucked themselves.
This particular model for LAPD comes with an Apex trigger (or at least the trigger shoe) as OEM.
LAPD doesn’t transition the entire Dept when the switch guns. The new gun is what is issued to new hires for the life of the contract. In-service officers previously qualified on other striker fired platforms such as Glock and Smith and Wesson have the option of keeping their existing guns or transitioning to the FN at their own expense if they wish. LAPD previously had Glocks in 40 and 9mm and dropped them for S&W M&P 9mm, which is now being “replaced” by the FN. So LAPD is very familiar with Glocks.
Without getting into the weeds on the VP9, the HK VP9 has not fared well in US LE Agency trials and I’m not aware of any significant institutional users in the US.