News | Dec 5, 2019

Navy engineer invents ‘flash corridor,’ improves burn profile of ammo

A soldier collects spent brass casings in Alaska.

Alejandro Peña/Air Force

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 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.

The flash corridor can be added to traditional “brass” ammunition or manufactured as part of polymer ammunition. (Navy illustration)

Business Opportunity

Inventor Jonathan VanBuskirk is a mechanical engineer at the Naval Surface Warfare Center’s Crane Division, a defense lab located in Indiana that has a small arms research division supporting U.S. warfighters.

Through a technology transfer license agreement, this patent-pending technology and other inventions from the lab are available to private companies who would make, use, or sell them commercially.

TechLink, the Department of Defense’s national partnership intermediary for tech transfer, guides private companies and startups through the license agreement process at no cost.

Sean Patten, a senior technology manager at TechLink, works closely with the Navy lab’s tech transfer office, helping companies evaluate Navy tech and understand how they can benefit.

“The commercial and military potential of the flash corridor invention makes it a good candidate for tech transfer, and the intellectual property rights will be very valuable to private companies who want to use it to bring new or improved products to the market,” Patten said.

For more information on licensing Navy technology contact Sean Patten at or 406-994-7721.