Heckler & Koch MP5 SD6 9mm silenced sub machine gun

01. Original name Heckler & Koch MP5 SD6  
02. Other official names Maschinenpistole 5 Schalldämpfer  
03. Popular names MP5-SD  
04. Chamberings 9 x 19mm Parabellum  
05. Designed by Heckler & Koch GmbH -Tilo Möller, Manfred Guhring, Georg Seidl, Helmut Baureuter  
06. Design date 1974  
07. In service date(s) 1974 – present  
08. Adopted by The MP5 is in use with the majority of modern militaries and can be found in over 80 countries  
09. Production quantities   
10. Mechanism Delayed opening friction roller breech, firing from the closed bolt position (bolt forward)  
11. Weight 7.5lb (3.4kg)  
12. Mountings The MP5SD has iron sights. Rear: rotary diopter drum; front: hooded post. The rear sight has four apertures of varying size which are used to adjust the diopter system. Interchangeable polymer trigger module allows for installation of different trigger groups. The MP5SD6 has a selectable 3-round burst facility; uses standard MP5 15 and 30-round box magazines  
13. Practicality in action The MP5 has a reputation for accuracy, reliability and stability due to its closed bolt operating system. The MP5SD model has the benefit of noise reduction using the built in suppressor with the additional benefit of dissipated muzzle flash  
14. Comments / Other information The MP5SD incorporates a lightened bolt to ensure reliable cycling and a shortened 146 mm (5.7 in) vented barrel surrounded by metal mesh packing within the aluminium shroud followed by conical baffles in the forward chambers. This system allows the use of standard 9mm supersonic ammunition at subsonic velocity, the vented barrel bleeds off propellent gas to reduce the bullet speed so it does not generate a sonic shockwave. The design of the suppressor allows for the firearm to be discharged with water inside should it be used in or near to water. Barrel patent drawing: https://en.wikipedia.org/wiki/File:Patent_DE1553874_07-Oct-1971_Handfeuerwaffe_mit_Schalldaempfer_Heckler_und_Koch.png. Heckler & Koch MP5 SD6 9mm Sub Machine Gun (Germany) (post-WW2) Silence version of MP5 Sub Machine Gun: chambered for the 9mm Parabellum round; cyclic rate about 800rpm, has selectable 3-round burst facility; uses standard MP5 15 and 30-rouind box magazines; Weight without magazine 7.7lb; uses the MP5 delayed opening friction roller breech.