120mm M933 and M934 HE Mortar Cartridges: Data Sheet
The M933 and M934 are the high-explosive (HE) cartridges of the US 120mm M120 towed and M121 carrier-mounted mortar system. Both were type classified in May 1992 and use the same steel shell body. The only difference is the fuze:
- M933: point-detonating fuze M745, which functions on impact.
- M934: multi-option fuze M734, set by the crew for proximity, near-surface burst, impact, or delay.
The M934 with its M734 multi-option fuze, from TM 43-0001-28, p. 4-105.
At a glance
| Designation | Cartridge, 120mm: HE, M933 with Fuze, PD: M745 / M934 with Fuze, Multi-option: M734 |
|---|---|
| Type classified | TC-Standard, May 1992 |
| Weapon | M120 and M121 120mm mortar system |
| Complete round weight | 31.2 lb |
| Length | 27.99 in. (710.95 mm) |
| Shell body | Wrought carbon steel |
| Filler | Composition B, 6.59 lb (2.99 kg) |
| Propelling charge | M230: four horseshoe-shaped felt-fiber containers around the fin shaft |
| Fin assembly | M31 |
| Ignition cartridge | M981, with a percussion primer |
| Color | Olive drab with yellow markings |
| DODAC | 1315-C623 (M933), 1315-C379 (M934) |
All figures from TM 43-0001-28, pp. 4-103 to 4-106.
How the round goes together
Reading the cutaway from nose to tail: fuze, adapter, booster, the Comp B-filled body with its obturating ring, then the long fin shaft. The four propellant containers clip around the shaft just ahead of the fins, and the ignition cartridge seats in the end of the shaft. Dropped down the tube, the round strikes the firing pin. The ignition cartridge fires through holes in the shaft and lights the propellant.
The drawing gives two lengths: 710.95 mm for the complete round and 642.5 mm from the fuze shoulder to the tail.
The M933 with the M745 point-detonating fuze, from TM 43-0001-28, p. 4-103.
The replica
Our 120mm mortar replica is modeled at the real round's 711 mm length. It is a four-piece print (base, top, tail fin and fuze) that screws together, with the M734 fuze's PRX, NSB, IMP and DLY settings molded in. It comes painted in HE or COMP-B or unpainted, as a whiskey stash or piggy bank, and as a custom version with a laser-engraved base placard. All 3D printed, all plastic.
Sources
- TM 43-0001-28, Army Ammunition Data Sheets: Artillery Ammunition, Headquarters, Department of the Army, 28 April 1994, through Change 11 (27 October 2003), pp. 4-103 to 4-106. Distribution Statement A: approved for public release. Find it in our Ordnance Reference Library.
Redleg3D makes 100% plastic, inert display replicas. This page is for history, collecting and identification only. If you ever find real ordnance, don't touch it: leave the area and call 911.