The cartridge .223 REM (5.56×45) is used for sporting and hunting shooting through bolt-action and semi-automatic rifles and carbines. The cartridge keeps its qualities under various climatic and weather conditions independent of the season and at a temperature from – 20 to + 50 C. The cartridge complies with CIP requirements. The cartridge is settled upon chambering until the case shoulder rests against the chamber one. The firearm models H&K SL-8, OA-15, REMINGTON, CZ527, and RUGER MINI 14 are deployed to run the acceptance tests of cartridges. The phosphate polymer coating cartridge case is bottled-shaped with non-projecting flange and made of steel. The bullet of .223 REM (5.56×45) consists of two elements, i.e.: copper or bimetal jacket lead core Spheroid powder.