The Defence Research and Development Organisation (DRDO) has initiated a project to develop polymer-cased ammunition (PCA) for small arms, replacing traditional brass cartridges that have been in use for nearly two centuries. The shift aims to reduce the weight of ammunition by 25-30 percent, directly lightening the load carried by soldiers and easing logistics, according to experts.
Polymer Cased Ammunition: How It Works
In PCA, the shell is made of high-tensile polymers capable of withstanding the heat and physical forces of ballistic action, including loading and ejection. The cartridge's base rim and projectile remain standard metal components. The use of polymers cuts production costs and significantly reduces cartridge weight.
For context, a 5.56mm brass cartridge used in the INSAS rifle weighs about 185 grams, while a 7.62mm AK-47 round weighs around 250 grams. In wartime, a rifleman is typically authorized 100 rounds, though this varies by mission or static duty, according to army officers.
Benefits Over Brass: Lighter, More Durable, Cooler
An article published by the US Marine Corps, which is actively introducing PCA, notes that it is significantly lighter and easier to haul than traditional brass-cased ammunition. Polymer also offers greater durability compared to brass and other metals commonly used in weapon systems. Additionally, it absorbs heat expelled from the casing, preventing the weapon from overheating and allowing soldiers to fire for longer periods.
DRDO's Project Scope and Execution
The project is being executed by DRDO's Armament Research and Development Establishment (ARDE), which is mandated with designing and developing conventional arms and ammunition, in collaboration with industry partners. DRDO sources said that the goal is to replace brass cartridges with PCA. Initially, the project focuses on small arms like pistols, carbines, and rifles, but could later be expanded to cover larger caliber weapons.
Difference from Plastic Bullets
PCA is distinct from what is commonly called a plastic bullet, which has been used by law enforcement for crowd control. While PCA is lethal, firing a metal slug, a plastic bullet is non-lethal with a slug made of plastic or hardened rubber.
Historical Context
The introduction of polymer cartridges has gained prominence recently, with militaries in countries like the US and Australia transitioning from experimental development to operational service. However, PCA was first developed in the early 1950s and initially used in shotgun cartridges traditionally made of paper or cardboard. The brass cartridge it replaces dates back to 1812, when Frenchman Jean Samuel Pauly created the first integrated cartridge using a brass base. The first self-contained metallic cartridge was invented by French gunsmith Louis-Nicolas Flobert in 1845, and after further improvements, it was widely adopted from the 1850s.
