Treadwell SP-X
| Treadwell SP-X | |
|---|---|
 The Treadwell 9mm “SP-X” Sub-Machine Gun | |
| Type | Submachine gun |
| Place of origin |  Empire of Exponent |
| Service history | |
| Used by | Blackhelm Confederate Army and Police |
| Production history | |
| Designer | Marcus Treadwell |
| Designed | 1980s |
| Manufacturer | Treadwell Arms |
| Produced | 1984–present |
| Specifications | |
| Weight | 2.5 kg |
| Length | 607 mm stock extended / 387 mm stock folded |
| Barrel length | 208 mm |
| Cartridge | 9x19mm Parabellum |
| Caliber | 9mm |
| Action | Blowback |
| Rate of fire | ~1000 rounds/min |
| Effective firing range | 50–100 m |
| Feed system | 22 or 32-round detachable box magazine |
| Sights | Iron sights Single Point IR sight |
The 9 mm Treadwell SP-X submachine is produced in both semi-automatic for security and automatic for military use. The automatic version fires from the open bolt, while the semi-automatic version fires from the closed bolt. Both versions are blowback operated. The bolt wraps around the rear of the barrel when closed, saving on overall length. The cocking handle is located at the top of the receiver. The SP-X has an ambidextrous safety lever and a separate fire mode selector built into the trigger. The military-use version can be fired in single-shot mode by partially pressing the trigger, or in full-auto mode by fully pressing the trigger. There is also an interceptor notch that catches the bolt if it is released during the cocking but prior to activating the sear. The weapon is coated with a rust-resistant coating which doubles as a dry lubricant.
Owing to a wide variety of muzzle devices (including silencers, heat shields, and even rifle grenades), the weapon can be used to fire non-lethal and explosive projectiles by the means of blank cartridge, as well as normal ammunition. The gun also features an underfolding buttstock, made from stamped steel. The standard sights are of open type, but the SP-X can be equipped with laser aiming modules and collimating sights.The gun fires at a relatively high rate of about 1000 rounds per minute, and is well-balanced and reasonably accurate with a barrel length of 208 mm (8.2 in). It can be fired single-handedly by folding the stock forward to form a solid foregrip.