The Effects of Steel Cased Ammunition

Traditionally the case containing gunpowder, primer and bullet is made of brass, a soft alloy of copper and zinc. Rising commodity prices led some ammunition manufacturers to look at alternatives to brass. Two companies, Wolf and Barnaul, produce steel-cased ammunition, predominantly in military calibers, for the civilian shooting market. Steel, being harder than brass, concerns some shooters due to the potential for greater wear on gun parts.

  1. Lacquer and Polymer Coatings

    • Wolf and other manufacturers of steel-cased ammunition coat their ammunition to prevent corrosion during shipping and storage. Originally Wolf and Barnaul used lacquer. During high volume shooting the lacquer softens and begins to collect in the chamber. When allowed to cool around a chambered round, the lacquer hardens and the case becomes stuck. Most manufactureres shifted to a polymer coating to reduce this effect.

    Steel vs. Brass in a Chamber

    • Brass being a softer metal expands to the limits of a chamber when fired. This ensures that all of the gases produced by the gunpowder travel down the barrel and not into the chamber. Steel cases resist the impulse to expand leaving gaps from the shoulder of the case to the rim allowing some of the gas into the rest of the chamber causing carbon buildups. The effect causes the rifle to shoot dirtier than normal and in some cases fails to extract.

    Extractor Problems

    • The extractor on a firearm is designed to grab an empty case by the rim and eject it from the chamber after firing. On softer brass cases, when a case gets stuck, the softer metal gives. Case or rim separation occurs but damage to the extractor is minimal. When steel cases get stuck damage or excessive wear on the extractor occurs, eventually leading to malfunctions.

    Reloading Problems

    • Most manufacturers use Berdan primers in their steel cased ammo. Berdan primers use two flash holes instead of the one used by Boxer primers. Common reloading tools in the United States do not allow for decapping Berdan primed cases. The steel cases themselves create problems for reloaders as resizing dies and presses are designed for softer brass cases and not steel.