Heckler & Koch MP5
9x19mm or 10mm Auto or .44 S&W
Originally produced in the 1960s there are many variants. This is one of the most widely used submachine guns in the world, used by many special forces & SWAT groups including SAS, NZ SAS and NZ Special Tactics Group.
The two versions shown are:
Top: a Personal Defence Weapon (PDW) variant of the shorter (K) model with a removeable stock, in this case with a synthetic shoulder stock and flash suppressor
Bottom: an SD variant designed with an integrated silencer and retractable stock, used by Special Forces