The MP5K, a super-compact variant of the MP5, is lightweight, smooth shooting, and nimble in the hands. It’s sort of akin to an AR-15 pistol in that regard, but chambered in a handgun caliber instead of something like 5.56.  But as ARP fans will tell you, while the platform is easy to conceal, handling lacks a little.  On that note, here are 3 ways you can upgrade your MP5K...