5.7x40mm AVA
5.7x40mm EC | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Type | Rifle | |||||||||||
Place of origin | Entente Cordiale | |||||||||||
Service history | ||||||||||||
In service | 1978–present | |||||||||||
Used by | Sieuxerr Sylva New Tyran EC | |||||||||||
Wars | Various | |||||||||||
Production history | ||||||||||||
Designer | Saint-Étienne Arms Manufacturer | |||||||||||
Designed | 1977 | |||||||||||
Manufacturer | MAS Manurhin Various other plants | |||||||||||
Specifications | ||||||||||||
Case type | Rimless | |||||||||||
Bullet diameter | 5.7 millimetres (0.22 in) | |||||||||||
Neck diameter | 6.5 millimetres (0.26 in) | |||||||||||
Shoulder diameter | 8.3 millimetres (0.33 in) | |||||||||||
Base diameter | 9 millimetres (0.35 in) | |||||||||||
Rim diameter | 9 millimetres (0.35 in) | |||||||||||
Rim thickness | 1.5 millimetres (0.059 in) | |||||||||||
Case length | 40 millimetres (1.6 in) | |||||||||||
Overall length | 56.4 millimetres (2.22 in) | |||||||||||
Rifling twist | 1:12 | |||||||||||
Primer type | Small rifle | |||||||||||
Ballistic performance | ||||||||||||
| ||||||||||||
Test barrel length: 500 millimetres (20 in) Source(s): Arsenal Munitions Test Range |
The 5.7x40mm EC is a rimless, bottlenecked, center-fired intermediate cartridge family. Designed in the mid-1970s, the 5.7mm EC and 7x51mm EC cartridges and their weapons would become standardized across the Entente and Entente-aligned nations by the 1980s.
History
Development of an intermediate cartridge began in the 1950s following capture and analysis of former-Ostlandic small arms, notably the StG-44 and the 7.92x33mm Kurz, and other, smaller production run experimental weapons. Another weapon that the Sieuxerrian Army showed great intrest in was the Hallian M1 Carbine and its .30 Carbine cartridge. Testing of these two rounds would lead to a number of other experimental rounds. Along with this, a series of new rifles and light machine guns were beginning development. However, development slowed as instead a replacement for the various rifle cartridges that had been in service during the PSW was prioritized. Using new understandings of ballistic theory, a 7mm round was developed and put into service, the 7x51mm EC cartridge.