A 5.45x39mm BT gs (GRAU Index - 7BT4) cartridge with a 3.1 gram armor-piercing tracer bullet with a heat-strengthened steel core with a bimetallic jacket, in a steel case, intended for target designation and fire adjustment in battle (Trace color: Red). This BT (Broneboynaya Trassiruyushchaya; "Armor-piercing Tracer") bullet its an improved version of the used in the 5.45x39 mm T gs cartridge (GRAU Index - 7T3), since the lead core was replaced by one of heat-strengthened steel, providing automatic firearms with penetration capabilities against basic ballistic protections as well as excellent results against intermediate models, however, due to its design, it has a significant bounce probability off various surfaces.
x2
