Editor’s Note: HK partnered with Umarex to bring an HK-authorized rimfire version of the legendary MP5. Users get an economic trainer pistol with familiar controls and unmistakable looks at a more affordable cost. The 8.5-inch barrel is threaded, which makes suppression easy. Recoil is minimal, making these guns great for those looking for a fun .22 LR plinking experience or for training purposes.  The MP5 .22 LR accessories are often compatible with its centerfire counterpart, allowing users to attach optics, lights, and suppressors.