7.62×51mm CETME

The 7.62×51 CETME round is a variant of the 7.62×51 NATO rifle cartridge with a plastic-cored lead bullet and a reduced propellant charge. It was produced as a joint venture by the Spanish Government design and development establishment known as CETME (Centro de Estudios Técnicos de Materiales Especiales, or "Center for Technical Studies of Special Materials") and the German arms manufacturer Heckler & Koch. The 7.62×51 CETME and the 7.62 NATO cartridges are almost identical, with the only difference being the projectile and the amount of propellant loaded into the cartridge.

During the development of the CETME rifle, it was decided by CETME that their new weapon would be chambered in a .30-caliber rifle cartridge with a short case and lesser powder charge in order to increase the manageability of the rifle during full auto fire. The 7.92x33mm Kurz was the original basis, but the 7.92x40mm CETME M53, a more powerful experimental cartridge developed by CETME, was also tried. Eventually they decided on a variant of the new 7.62×51mm NATO cartridge that they designated the 7.62×51mm CETME. The 7.62mm CETME had a lighter full-metal-jacketed, plastic-cored lead bullet with a reduced powder charge.

While designing the CETME Modelo B and under recommendation of H&K, the decision was made that the updated version of the original CETME Modelo A would chamber the more powerful 7.62×51 NATO cartridge. When the Modelo B was adopted by the Spanish military as the Modelo 58 in 1958, the full-power 7.62×51 NATO cartridge came to replace the 7.62×51 CETME as the standard rifle cartridge.

Weapons

 * Santa Barbara FR7 Fusil Reformado Bolt Action Rifle (Mauser Model 1916 converted to 7.62x51mm NATO)
 * Santa Barbara FR8 Fusil Reformado Bolt Action Rifle (Mauser Model 1943 (Mauser K98k) converted to 7.62x51mm NATO)
 * CETME Modelo A Fusil de Asalto - Adopted by the Spanish military in 1957.
 * CETME Modelo B Fusil de Asalto / Modelo 58 Fusil de Asalto - Adopted by the Spanish military in 1958.