7.7 Japanese

Here are a few of my 7.7 Jap rounds

7.7 explosive Rimmed

7.7 Jap Tracer Rimmed 1928

Rimmed ball in MG link

Semi Rimmed explosive


Thanks Steve, I learn again. Did not know they made a rimmed version of the 7.7 Just assumed the various 7.7 guns used the same round.

Nice examples of T87/T92 IJN ammunition, 7,7 x56R ( aka .303 British).

The Imperial Japanese Navy started experiments with imported Vickers and Lewis guns back in the early 1920s, and used Kynoch-made .303 ammo.
They developed their own versions of the Vickers Aircraft gun (belt fed) for use in Navy Fighters, and copied the then-existing (WW I designed_) Prideaux patent steel disintegrating Link. Japanese made links are devoid of any markings ( British and Aussie ones have makers initials and “mark” nos.

The Airforce also imported .303 guns etc, but went with the T89 semi-rimmed Air Loading, but using the .303 style bullet, and used Nambu developed Flexible guns, but Vickers Aircraft guns in both Wing and Cowl mounts…in Semi-rimmed chambering ( One gun design, two different cartridges) Both Naval and Army Airforce Vickers guns were “Type 89” ; original BSA-made Lewis Guns were “T87” and then the IJ Navy made their own as “T92”; British and Japanese Guns were not Interchangeable in their parts specs, although the ammo was.

The Explosive round in 7,7x56R used the “double jacket” construction, with the explosive charge placed between two jackets, one inside the other, the inner one being lead core filled. On Impact with an aircraft engine or fuel tank ( or even thicker body parts) they would crush and explode.

Do NOT try to dismantle these by Inertia Puller or Collet Puller…either method can result in detonation, sufficent to take off a few fingers, an eye, or even kill one.
BTW, as was common in IJN [practice, rounds carry a headstamp of the Naval Arsenal( base), a “trimester or quadrimester” indicator (Roman Nos) and the Japanese Imperial History year ( 99 == 1939, etc) (not the Showa year, as used on Pistols, etc) . By about 1942, they dropped the headstamps as well.

Doc AV
AV Ballistics.


They loaded three 7.7 versions, rimmed aka 303, semi rimmed, and rimless.


Thank you for that information as I only had a bit of info on those rounds.