SIG AMT/PE57/550
Stoner SR-25
Barrett .50
AR15/M16 FAQs
Bushmaster Armpistol
M96 Expeditionary


Information Compiled and Mirrored from Nammo

12,7 mm Ammunition Family

Recent modifications to the 12,7 mm machine gun system have made it considerably more effective as an offensive and defensive weapon system. For example, the new "softmount" dramatically increases the accuracy with less than 18 kg of added weight. Furthermore, the new family of Multipurpose and Armour Piercing rounds (originally designed for the .50 cal M2 machine gun) have a unique penetration and incendiary effects. This gives the overall gun system the equivalent firing power of a 20 mm projectile to include such targets as helicopters, aircrafts, light armour vehicles, ships and light fortifications.

Product information

12.7 mm

All three rounds have the same weight and ballistic performance. Therefore they can be linked together with no adverse effect on the ballistic. Furthermore the rounds can be delivered in the extremely accurate Grade A configuration, making each an excellent choice as a sniper round.

Performance Data
MP NM140
MP-T NM160
AP-S NM173
11 mm Armour in 45o at 1000 m
11 mm Armour in 45o at 1000 m
11 mm Armour in 30o NATO at 1500 m
Approx. 20 effective fragments after hitting 2 mm Dural
Approx. 20 effective fragments after hitting 2 mm Dural
Incendiary effect
Ignition of JP4 and JP8 ammunition
Ignition of JP4 and JP8 ammunition
Accuracy Grade A
At 550 m (Mean radius)
< 15 cm
< 25 cm
< 15 cm
Red tracer 50 – 1500 m
All types are safe in transport, storage and handling. Drop test from 15 m with safe firing after drop. Comply with requirements in NATO standards and Stanag for 12.7 mm.

12,7 mm x 99 MP NM140 (US nom. Mk211 Mod 0)
12,7 mm x 99 MP-T NM160
12,7 mm x 99 AP-S NM173
Cartridge length:
138,43 max
Projectile diameter:
Projectile weight:
43-47 g
Muzzle velocity:
Approx. 915 m/s (Browning M2)

The ammunition can be used in all standard 12,7 mm (.50 cal) weapons like Browning M2 and M3, M3P, sniper rifles similar to Barrett M82A1 and can also be with changed cartridge case used in 12,7 x 107 weapons.

Target consisting of an initial plate of 2 mm Dural wth witness screens of 2 mm Al with airspace 0,4 m. Fragmentation screen in rear of 1,25 mm mild steel placed 2 m behind the initial plate

Standard US 12,7 mm API-M8 gives only one hole through all plates.

MP is functioning about 20 - 30 cm inside the target giving approximate 20 fragments through the 1,25 mm steel plate.



The Multipurpose Concept was developed in the late 1960’s based on requirements from the Norwegian Defence Forces for a more cost effective ammunition for use in 20 mm airborn guns and airdefence guns. Nammo Raufoss AS holds all patents rights on the concept.

The Multipurpose (MP) ammunition has been developed to cover a wide range of targets which results in easier logistic handling. Earlier use of different ammunition types (HE, HEI, AP, API, APHEI, etc.) can now be replaced by one type; namely the MP concept.

The unique MP design exclude the use of a complex expensive fuze because the need for detonators and sensitive high explosives have been eliminated. The properties of insensitive incendiary charges and secondary high explosives (RDX and HMX based explosives) are combined in a pyrotechnic initiated ammunition with excellent safety characteristics.

Based on the 20 mm MP, the design has been adopted to various calibers ranging from 12.7 mm to 40 mm.



The Multipurpose Concept is safe in transport, storage and handling. The ammunition is drop safe from more than 15 m, and is completely safe to handle after the drop and can be fired from the gun without any safety risk. The round will function reliably when hitting the target.

Adobe PDF Showing Nammo Raufoss Testing Facility


Last Modified on January 12, 2000