枪弹由弹壳、底火、发射药、弹头四个部件组成。由于弹头的结构与功能不同,因而有不同的弹种。大口径机枪弹主要有穿甲燃烧弹、穿甲燃烧曳光弹、次口径脱壳穿甲弹、爆炸弹等。在功能上,穿甲弹有一定的穿甲能力,但没有爆炸作用;爆炸弹只有爆炸作用而穿甲能力很差。 与以往相比,现代战争中目标已有了很大变化。就地面目标而言,步兵大量使用装甲车辆(如步兵战车、装甲输送车、装甲侦察车等)协同坦克作战;就空中目标而言,有飞机、直升机、巡航导弹及各种无人驾驶的飞行 Bullets by the shell, bottom fire, launch drugs, warheads four components. Due to the structure and function of warheads are different, so there are different types of shells. Large-caliber machine-gun mainly has armor-piercing fire bombs, armor-piercing tracer bombs, sub-caliber armor piercing bombs and explosives bombs. Functionally, the armor-piercing projectile has a certain armor piercing ability but no explosive effect; the projectile has only an explosive effect and the armor-piercing capability is poor. Compared with the past, the goal of modern warfare has changed a lot. In the light of the ground targets, infantry units are heavily engaged in tank operations using armored vehicles (such as infantry fighting vehicles, armored vehicles and armored reconnaissance vehicles); in the case of air targets, infantry, helicopters, cruise missiles and various unmanned flight