5.45x39mm ammunition is a type of intermediate rifle ammunition originally developed by the Soviet Union. It is designed for use in firearms such as the AK-74 and its variants, as well as the RPK-74 light machine gun.
The 5.45x39mm cartridge is similar in size and shape to the 5.56x45mm NATO cartridge used by the United States and its allies, but the 5.45x39mm cartridge uses a smaller, lighter bullet. The standard bullet weight for 5.45x39mm ammunition is 53 grains.
The bullet design for 5.45x39mm ammunition can vary, but typically features a steel core surrounded by a lead or copper jacket. This bullet design provides excellent penetration and accuracy at medium ranges, making it a popular choice for military and law enforcement applications.
5.45x39mm ammunition is loaded with a consistent powder charge and primer, ensuring reliable performance and consistent accuracy. The cartridges are typically steel-cased and berdan-primed, which can make them less expensive than brass-cased and boxer-primed cartridges.
Overall, 5.45x39mm ammunition is a reliable and accurate intermediate rifle ammunition that is commonly used in military and law enforcement applications. Its small size and light weight make it an ideal choice for use in lightweight firearms such as the AK-74, while its excellent penetration and accuracy make it an effective choice for medium range engagements.