Military

Cartridge, 105mm, M548, HERA

Army 105mm howitzer cartridges are semi-fixed and fired from rifled howitzers. A complete service round consists of a projectile, fuze, cartridge case with primer and propelling charge. Cartridges are issued fuzed or unfuzed.

High Explosive Rocket Assisted (HERA), M548 rocket motor spike may be contaminated with a yellow crystalline substance composed of 2-Nitrodiphenylamine. Double base cast propellants used in rocket motor also have a history of exuding a NG plasticizer that tests have proven to be quite insensitive. Both may give appearance of corrosion but presence of either substance is not a defect. Annotate occurrence on Depot Surveillance Record Cards for information purposes.

Projectiles with damaged threads that pass gaging are not defective. A concentricity gage (deep cavity) is not available for M548 HERA cartridges. Utilize an inert M514A1 proximity fuze to assure acceptable concentricity and depth of fuze well.