Army to ditch WWII-era wooden ammo boxes for new lightweight design

The Army is replacing its decades-old wooden ammunition boxes with a lighter polymer design, marking the first major change to rifle ammunition packaging since World War II, according to a recent service statement. 

The new SixPAC, a container to transport rifle ammunition, is being developed for the Army’s 6.8 mm rounds, which are used by the new M7 rifle and M250 automatic rifle, the Development Command Armaments Center said in an Aug. 26 statement. 

The existing packaging system places steel ammunition containers inside wooden outer boxes that require manual assembly and are heavier as well as susceptible to mold, according to the statement. 

Soldiers stack wooden ammunition crates during an exercise at Fort Magsaysay, Philippines, April 3, 2025. Army officials say the switch to an ammunition holder with a polymer-and-steel design will cut weight, speed up manufacturing and reduce supply-chain risks tied to wood. (Tristan Moore/U.S. Army)

Preserving the wooden boxes also requires chemical treatments, which can have environmental impacts and contribute to supply disruptions. 

The new carrier is meant to eliminate those drawbacks while also allowing soldiers to carry more ammunition in each container at a lower overall weight. 

The Army did not immediately respond to questions about the weight and ammunition capacity of the new containers. 

Testing of the new containers by soldiers began in 2024 and 2025, and troops have responded positively to their increased ammunition capacity, the statement said.

The SixPAC will use a steel outer layer with a lightweight polymer interior compartment, according to the statement.

“Polymers are unique,” said Edward Lucas, a mechanical engineer who helped design the new containers. “You can modify them, include additives that improve impact performance, stiffness or dimensional stability.” 

The inner compartment’s polymer design is still “undergoing refinement,” though the Army plans to continue investing in the development of polymer packaging designs, according to the statement.