In complete contrast to the highly engineered and expensive Thompsons the M3A1 was based on the Sten and construction was all metal with most parts simple steel stampings welded into place. A telescopic wire butt was fitted there is no safety and the gun could only fire fully automatic. Sights were very rudimentary and cocking achieved by inserting fingers into the exposed breech block and pulling it backwards. The M3A1 could be changed from 0.45 in to 9 mm by changing the barrel, magazine and breech block. The gun on display is a 9 mm Chinese copy of the M3A1 known as the Type 36.
Marks and Stamps: (L side of mag housing) manufacturers logo Chinese characters Serial no| Accession Number: 164 | Period of Use: 1944 - present |
| Type: Machine pistol/SMG | War Zones: Second World War; Korea; Vietnam |
| Country of Origin: China | Type Date: 1944 |
| Manufacturer: Unknown | Serial Number: 018625 |
| Manufacture Date: Unknown | Calibre/Ammunition: 9mm Parabellum |
| Weight: 3710g | Length Overall: 756mm |
| Cyclic Rate: 400rpm | Length Barrel: 203mm |
| Deactivation Certificate Number: DA 43032 |