.30 caliber Browning M2 aircraft machine gun on training hard mount.

The Browning .30 caliber is a work of art. It weighs nearly 1/3 less than it's ground cousin weighs. Virtually every part has been machined to reduce its weight. With a 300 mile per hour slip stream to cool it, the barrel can be thin and light. The military version is the Browning ANM2, the Colt commercial version is the MG40. It was used in both single and twin mounts, and as a fixed wing gun up until WW2 when it was realized that the .30 caliber round was simply too light to take out modern fighter aircraft. It was replaced but the .50 caliber M2. John Browning worked with the Belgian military and developed the FN series of guns, the FN30 ground gun and the FN38 & 39 aircraft guns. During WW2 the .30 caliber Browning was primarily used in training.

Shown here are .30 caliber bolts which illustrates the basic differences between ground and aircraft design. The aircraft bolt (1) has been reduced in height and width and excess material has been removed. The bolt from the ground gun (2) has had only the machining necessary to accommodate its component parts. The lightened bolt gives the aircraft gun a significantly higher rate of fire. (Source, photo at left: Steve Fleischman for Small Arms Review )

A gunnery school GI holding a .30 caliber ANM2.

The Browning 1919 -
the heavy barreled .30 caliber Browning.
The Browning 1919A4 HB (heavy barrel)
ground machine gun on an M2 tripod.

The Colt Browning MG40 with slotted barrel shroud.

The Browning ANM2 fixed aircraft with a step down style barrel shroud.

The A-24 Dauntless had twin mounted
.30 caliber ANM2 machine guns

Navy gunner with ANM2 .30
on a ring mount.
Artwork from WW2 era Life magazine ads depicting the ANM2.
(These are worth enlarging - just click on one)

1) Special enhanced cooling jacket with increased number of holes and expanded diameter at the throat of the barrel. There are 86 holes in 6 rows.
2) Most common military issue. 52 holes, 4 rows.
3) Slotted military that was also used on military guns. 27 holes, 6 rows
4) British MK2. 24 slots, 6 rows.
(Source: Steve Fleischman for Small Arms Review)

Shown above is a pair of ANM2s on a Mark 2 buffered mount.

At right are twin Belgian Browning FN M1932s on a hard mount. Note the front wind vane sight. More about that in the Sights section.

Colt MG40 schematic and parts list. Click on image to enlarge.