US Army modernises ammunition packaging with SixPAC

The US Army has unveiled SixPAC, a new packaging system for small-calibre ammunition that combines lightweight polymer containers with a rugged steel outer pack. Developed by the US Army Combat Capabilities Development Command Armaments Center, the system represents the first major overhaul of small-calibre ammunition packaging since the Second World War.

SixPAC was initially developed for 6.8 mm ammunition and consists of two lightweight polymer ammunition containers positioned inside a steel outer pack. Following its implementation for this calibre, the Army plans to adapt the concept across additional legacy small-calibre ammunition production lines.

Replacing traditional wooden packaging

One of the most significant changes introduced by SixPAC is the elimination of the traditional wirebound wooden overpack. The previous format required manual assembly, could be vulnerable to mould and deterioration, and depended on chemical wood-preservative treatments.

By removing the wooden component, the Army aims to reduce both manufacturing complexity and potential supply-chain vulnerabilities. The new combination of polymer and steel is designed to provide the durability required for long-term storage and operations across a wide range of climates.

Lighter packs improve military logistics

Reducing packaging weight was a central objective of the project. The polymer inner containers are lighter than conventional tactical ammunition cans, making them easier for soldiers to transport while also reducing the overall weight of ammunition shipments.

The steel outer pack also allows more containers and ammunition to be placed on each pallet, helping to reduce the logistical footprint associated with storage and transport. This is particularly important in military operations where available transport capacity can directly affect the volume of equipment and ammunition deployed.

Packaging designed for automated production

The Army also sees manufacturing flexibility as an advantage of the polymer design. The inner packs can be produced primarily through injection moulding, allowing manufacturers to use existing presses fitted with dedicated moulds rather than relying on highly specialised production lines.

This approach could broaden the potential supplier base and reduce reliance on a limited number of packaging manufacturers. It may also make production easier to scale during periods of increased demand, supporting greater resilience within the ammunition supply chain.

Testing supports future deployment

Soldiers tested SixPAC during 2024 and 2025, providing feedback on handling, transport and operational performance. According to the Army, responses were largely positive, particularly regarding the reduction in weight when ammunition has to be transported aboard aircraft, watercraft or by personnel in the field.

The polymer inner pack is continuing to undergo refinement, with the Armaments Center evaluating different designs and materials. One option under development is the patent-pending Polymer Rectangular Container, while additional concepts may also be assessed as the programme progresses.

Packaging becomes part of military supply-chain modernisation

SixPAC illustrates how packaging design can influence far more than product protection. In defence logistics, packaging weight, manufacturing capacity, pallet efficiency, material availability and long-term durability can all affect operational readiness.

By redesigning a packaging format that has remained largely unchanged for decades, the US Army is seeking to improve portability, reduce costs and strengthen its ammunition supply chain. The project also demonstrates how advanced polymers and more efficient manufacturing processes are increasingly being considered for demanding industrial and defence packaging applications.