Navy Engineer Invents “Flash Corridor,” Improves Burn Profile of Ammo

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December 17, 2019 | Originally published by Date Line: December 17 on

A U.S. Navy engineer has invented a tiny plastic tube that adds a flash corridor to cartridge ammunition, giving the propellant an improved burn profile.

In contrast to traditional rounds that burn back to front and forcing some propellant into the firearm’s barrel, when ammunition with a flash corridor is fired, the primer causes molten material to travel down the flash corridor to the propellant bed midway up the cartridge. The reaction then moves away from the initial reaction point in both directions, toward the rear and front of the cartridge, according to the Navy’s patent application first made public on Thursday.

“The retained propellant in the rear of the cartridge reacts within the cartridge so that less reacting propellant enters the barrel. Flash corridor inserts allow existing ammunition to be quickly and cheaply repurposed, while also improving performance over the original ammunition. A variety of insert shapes can be used, facilitating the use of alternative propellants and unconventional cartridge designs. While flash corridor inserts can be made of many materials (e.g., metals), polymer inserts are cheap and easy to manufacture,” the document states.