See Larry Vickers run a 10mm sub machine gun in this episode of Vickers Tactical.
The Mp5 is a wildly popular sub gun to get your hands on. The MP5 is normally chambered in the 9mm cartridge but for a very limited time HK made this particular model chambered in the 10mm cartridge. The Other main feature of this sub gun compared to the MP5 is the bolt catch. This version has the ability to lock the bolt to the rear. Likely due to high chamber pressures, the 10mm version of the MP5 was discontinued.
The 10mm MP5 has three selector modes that make this sub gun very user friendly. Safe, Semi, and Full auto. As you can see, Larry ran the gun on the range with minimal effort. The recoil was non existent and did not have much muzzle climb.
I would have loved to see the 10mm tested against some AR500 armor and see if this gun would be able to penetrate any of the body armor offered by them. Likely, the 10mm would not penetrate steel plates but the level 3A kevlar inserts may have been put through the paces.
Full-auto sub machine guns are always fun to see.