Evaluating the recommended safety distance of a recoil booster

Abstract

After a supplier course for the FN MINIMI 7.62 mm Tactical machine gun, it was noted that the accompanying recoil booster FN Herstal S. A. B0897 has a hole going through it, which is parallel to the line of fire. The hole has been identified as a potential safety hazard during training with blank ammunition, because if a foreign object (e.g. a small stone) gets stuck inside the hole it might be pushed out by the gas like a projectile. The Norwegian Defence Research Establishment (FFI) have investigated this potential safety hazard experimentally. By firing realistic improvised ammunition such as sticks, stones and ice towards a skin simulant, we observe dangerous perforations in the simulant. At two meters, the branches, ice and stones could reach velocities between 140 − 520m/s, 110 − 260m/s, and 715 − 800m/s respectively.

Etter leverandørkurs på «FN MINIMI 7.62 mm Tactical machine gun» ble det lagt merke til at den tilhørende rekylforsterkeren «FN Herstal S. A. B0897» har et gjennomgående hull i skuddretningen. Gjennom eksperimenter utført ved FFI har hullet blitt identifisert som en potensiell sikkerhetshetsrisiko. Skademekanismen oppstår hvis et fremmedlegeme setter seg fast i hullet, og blir akselerert til store hastigheter av kruttgassen. Ved å skyte realistisk improvisert ammunisjon, som kvist, stein og is, mot en hudsimulant har vi observert potensielt skadelige perforeringer. På to meters hold har vi målt at kvist, is og stein kan oppnå hastigheter mellom henholdsvis 140 − 520m/s, 110 − 260m/s og 715 − 800m/s.