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As outlined on the main Aircraft Guns page, AAC™ light machine guns all fire explosive rounds.  This cheat is intentional : to allow lightly armed (trainer) aircraft to be combat capable.  However fictional when applied to all LMG, explosive rifle calibre rounds did exist in the past.  Britain used explosive .303 rounds during WWI and Japan used 7.7mm and 7.92mm explosive rounds during the Second World War.  Here is some background information on the latter.


"Japanese Explosive Bullets" from Intelligence Bulletin, January 1945

The following intelligence report on Japanese explosive and incendiary ammunition was originally printed in the January 1945 issue of the U.S. Intelligence Bulletin.

Source :
Japanese Army Incendiary Bullet

Three different types of explosive and incendiary small-arms ammunition have been captured from the Japanese in the Southwest Pacific area. Because of the unusual characteristics of this ammunition, serious injuries sometimes have resulted when soldiers have tampered with it out of ignorance or curiosity.

Apparently first manufactured for use in Japanese aircraft or antiaircraft weapons, some of this ammunition has been found loaded in five round clips, presumably for use in infantry weapons. This ammunition—7.7-mm or 7.92-mm—may easily be recognized by color markings at the junction of the bullet with the cartridge or around the primer cap. It should not be handled carelessly

The three different types of ammunition are the 7.7-mm rimmed Navy round, the 7.7-mm semi-rimmed Army round, and the 7.92-mm rimless Army round.

Explosive and incendiary rounds may be recognized by the color marking as indicated in the following table:

Ammunition   Type Position of Color Mark   Color   Nose
7.7-mm R IJN HEI Primer cap Dull red
7.7-mm R IJN I Primer cap Green Pointed
7.7-mm SR IJA HE Case/bullet junction Purple Flat tip
7.7-mm SR IJA I Case/bullet junction Wine red Pointed
7.92-mm IJA HE Case/bullet junction White Flat tip
7.92-mm IJA I Case/bullet junction Red Pointed

The 7.7-mm rimmed Navy round is of two kinds—one is a combination high-explosive and incendiary, the other only incendiary.

Both types of the Army ammunition—the semi-rimmed and the rimless—are loaded either with an incendiary bullet or with a strictly explosive bullet (see illustration on page 32).

These bullets are not fuzed, but explode or ignite when the copper jacket is ruptured on impact with the target.

The explosive bullet may be recognized by its flat nose, but the incendiary has the pointed nose of an ordinary bullet. The explosive bullet is capable of blowing a 3-inch hole in a sheet of aircraft Duralumin.

Japanese Army Explosive Bullet


Source :


This fixed round of ammunition consists of a brass cartridge case and a high explosive projectile. The semi-rimless case is tapered, forming a neck which fits over the projectile. The top of the neck is coned into the cannelure of the bullet. The base of the case is recessed to take a simple percussion type primer, and the rest of the case is filled with a propelling charge of graphited nitro-cellulose grains, about half of which, in the specimens examined, had a very fine axial perforation. The brass projectile is cylindrical in shape with a truncated ogival nose. It contains a brass inner compartment, ogival in shape and open at the base, and a hammer consisting of a lead antimony plug encased in a brass sheath. The rear of the projectile is also open, the walls being turned in to retain the hammer.

Both the main projectile and the inner compartment. are filled with the explosive charge, a mixture of PETN and RDX. A white felt washer pressed into the base of the inner compartment protects the explosive charge from the effect of setback when the round is fired. When the projectile strikes a target, the hammer in the rear end sets forward crushing the explosive against the walls of both the inner and main compartments, causing the projectile to explode. The explosive bullet is capable of blowing a 3-inch hole in a sheet of aircraft Duralumin.

Caliber        7.7 mm (.303 in.)
Weight of complete round 26.15 grms.—.915 oz.
Length of complete round 3 3/32 ins.
Length of cartridge case 2 9/32 ins.
Weight of cartridge case (without percussion cap) 14.93 grms.—.523 oz.
Weight of projectile 10.69 grms.—.374 oz.
Length of projectile 1 15/32 ins.
Maximum diameter 0.310 in.
Thickness of main compartment walls 0.021 in.
Weight of main compartment 2.95 grms.—.103 oz.
Thickness of inner compartment walls 0.008 in.
Weight of inner compartment 0.20 grms.—.007 oz.
Height of inner compartment 0.390 in.
Length of hammer 0.700 in.
Weight of hammer 6.65 grms.—.233 oz.
Diameter of hammer 0.258 in.