The 7.7 mm "RU" Type was the famous Lewis machine gun imported from Britain starting in 1921. The design was modified to suit local Japanese manufacturing techniques and then produced as the 7.7 mm Type 92. These guns replaced the 6.5 mm 3rd Year Type MG on most ships.
Actual bore diameter was 0.303" (7.69 mm).
| Designation | 7.7 mm/87 (0.303") "RU" Type 7.7 mm/80 (0.303") Type 92 (Model 1932) |
|---|---|
| Ship Class Used On | Many ships of the 1920s and 1930s |
| Date Of Design | N/A |
| Date In Service | 1921 |
| Gun Weight | "RU" Type: 26.0 lbs. (11.79 kg) Type 92: 28.7 lbs. (13.00 kg) |
| Gun Length oa | "RU" Type: 50.5 in (1.283 m) Type 92: 39.4 in (1.000 m) |
| Bore Length | "RU" Type: 26.3 in (0.667 m) Type 92: 24.4 in (0.620 m) |
| Rifling Length | N/A |
| Grooves | N/A |
| Lands | N/A |
| Twist | N/A |
| Chamber Volume | N/A |
| Rate Of Fire | "RU" Type: 550 rounds per minute Type 92: 600 rounds per minute |
| Type | Fixed |
|---|---|
| Weight of Complete Round | N/A |
| Projectile Types and Weights | Solid bullet: 0.025 lbs. (11.35 gms) |
| Bursting Charge | N/A |
| Projectile Length | N/A |
| Propellant Charge | N/A |
| Muzzle Velocity | "RU" Type: 2,444 fps (745 mps) Type 92: 2,493 fps (760 mps) |
| Working Pressure | N/A |
| Approximate Barrel Life | N/A |
| Ammunition stowage per gun | N/A |
| Elevation | Distance |
|---|---|
| Maximum Range | "RU" Type: 1,000 yards (910 m) Type 92: 1,090 yards (1,000 m) |
| Effective Range | "RU" Type: 540 yards (490 m) Type 92: 328 yards (300 m) |
Data from:
- "World War II Fact Files: Machine-Guns" by Peter Chamberlain and Terry Gander
- "Japanese Cruisers of the Pacific War" by Eric Lacroix and Linton Wells II
Special help from Paul Roome
- 10 May 2006
- Benchmark
- 27 May 2012
- Updated to latest template