What ammunition did the fighter machine guns of World War II use?

Wartime aviation ammunition is mainly divided into the following categories: ordinary ammunition; AP; API; HE; HEI; T; APT; HET; I. There are also some less used ammunition types, such as APHE; APHEI; APCR, etc. Let’s talk about it one by one.

Normal ammunition: standard ammunition. Only available on aviation machine guns. Most of them are ammunition used on 7-8 mm caliber machine guns, which are the same ammunition used by the army.

AP: Armor-piercing projectile. The aviation armor-piercing bullets in World War II were traditional steel core bullets. At this time, there was no shelling design, so the armor-piercing ability of aviation AP bombs was relatively weak and completely relied on the kinetic energy given by the machine gun or aircraft cannon that fired it. Therefore, it was generally only used on aviation machine guns (the recoil of the aircraft gun was too large). If so, it will affect aircraft safety).

I: RS bomb. One of the most effective munitions against aircraft. Simple RS shells are only available on aircraft machine guns (because the warhead size is limited). The more common aircraft gun shells use API or HEI to enhance the destructive effect.

HE: High-explosive bomb. This is the primary ammunition used on cannons. The more common use of impact fuses. Since prefabricated fragmentation technology is not yet mature at this time, the destructive power of HE bombs basically depends on the weight and type of explosive charge.

T: Tracer bullet. It is used to mark the ballistic trajectory so that the pilot can make shooting corrections. Generally speaking, the tracer agent of tracer bullets also has a certain burning effect, but it actually cannot play the role of RS bullets. Tracer bullets can be used during the day and at night, and the brightness of the tracer is sufficient. Moreover, the tracer bullets of some aircraft guns can not only trace light, but also have the effect of pulling smoke, which is better when used during the day.

API: Armor-piercing RS bomb. The combination of armor-piercing bullets and RS bullets can enhance the destructive power. Anyway, it is impossible to use too thick armor on an aircraft, so there is no need to worry about weakening the armor-piercing effect.

HEI: High-explosive RS bomb. A combination of high-explosive bombs and RS bombs. Usually an incendiary component is added to the charge of a high-explosive bomb.

APT: Armor-piercing tracer bullet.

HET: High-explosive tracer bullet.

Although there are many types of ammunition, and each has its own use, it is impossible to equip aircraft with every type of bullet in actual combat - of course, a single type of ammunition is rarely used. -----. Generally speaking, aviation machine guns/cannons are only equipped with two or three types of ammunition with complementary performance in each battle. In principle, the combination should try to meet all possible situations.

The method adopted by the Luftwaffe of "loading different proportions of ammunition on an ammunition chain according to the type of mission" is relatively scientific. Take the 7.92mm MG17 machine gun as an example: when performing air combat missions, it uses 50% AP shells, 40% API shells and 10% HEI shells; when performing ground strafing missions, it uses the same ratio of AP and APT and API rounds to increase the destructive power against ground targets. Quite effective in actual use.

Later, the British also adopted this matching method. The ratio is: 50% AP shells and 50% I shells in air combat; 75% AP shells and 25% I shells in ground attack.

American bombers use .50 machine guns as self-defense weapons, which are relatively powerful. In 1942, the ammunition loading mode was the same as that of fighter jets: 40% AP bombs, 40% I bombs and 20% T bombs (...American ground crews are not generally lazy~) . By early 1944, this ratio had become 60% AP shells, 20% I shells, and 20% T shells. The reasons for the adjustment are the same as those faced by the RAF. It's just that the AP bullets of the American .50 machine gun are more powerful, so the ratio is not as disparate as the British. By the end of the war, the ammunition ratio was adjusted to 50% AP shells and 50% I shells. It is worth noting that this adjustment is actually caused by technological progress and has little to do with the Germans. At this time, American machine guns used new M8 API bullets, which not only ensured the combustion effect, but also functioned as tracer bullets. That's why the Americans canceled the proportion of dedicated tracer bullets on fighter jets.

Generally speaking, the Germans are the most careful in the proportion of ammunition configuration because the caliber of their aircraft guns is relatively large. Because this is directly related to the destructive effect of the aircraft cannon. Americans and British are more casual.