TERA rifle

TERA rifle
Type 2 TERA rifle
Type	Bolt-action rifle
Place of origin	Empire of Japan
Service history
In service	1943−1945 (Type 2)
Used by	Imperial Japanese Army Imperial Japanese Navy
Wars	World War II
Production history
Produced	1943−1945 (Type 2)
No. built	1,000 (Type 100 and Type 1) 19,000−21,500 (Type 2)
Variants	See Variants
Specifications
Cartridge	6.5×50mmSR Arisaka (Type 1) 7.7x58mm Arisaka
Action	Bolt action
Feed system	5-round stripper clip, internal box magazine

The TERA rifles (Japanese: 挺進落下傘小銃／挺身落下傘小銃, romanized: Teishin Rakkasan Shoujuu) were special Japanese takedown rifles developed for paratroopers of the Imperial Japanese Army and Imperial Japanese Navy. All designs were capable of either being broken down or folded into two parts and easily assembled or disassembled.

The Type 2 TERA rifle was officially adopted in 1943 by the IJA and saw use during the Battle of Leyte, but by the time it entered production, significant paratrooper operations had largely ceased.

Before the Pacific War, Japanese paratroopers only carried a Type 94 pistol and three hand grenades when jumping off their planes.^[1] The length of the Type 38 and Type 99 rifles made them impractical to be carried during deployment,^[2] so they were separately dropped in containers with their ammunition. The paratroopers often had difficulty locating and retrieving their rifles, forcing them to attack with only pistols, grenades, and whatever enemy weapons they could capture.^[1][3]

Development of dedicated paratrooper rifles were conducted by the 1st Laboratory of the 1st Army Technical Research Institute,^[4] which presented two different prototypes: the Type 100, which was designed to be carried broken down by a descending parachutist, and the Type 1 rifle, which could be carried with the buttstock folded.^[2][4]

While a handful of these prototypes were acquired by the IJA, neither were used during the Battle of Palembang, resulting in many rifles and heavier weapons of the IJA airborne forces being lost (a similar problem faced by German paratroopers during the Battle of Crete), and a renewed interest in developing a purpose-built paratrooper rifle.^[2][3]

In-mid 1942, the 1st Laboratory developed a practical take-down design based on the Type 100, but instead of using an interrupted screw, the detachable barrel was held in place with a tapered wedge. Tests conducted by the Futsu Proving Ground in October 1942 were satisfactory, and after a few tweaks, the Type 2 paratrooper rifle was officially adopted in May 1943.^[2][4]

The Toriimatsu factory of the Nagoya Arsenal built around 21,500 Type 2 rifles according to Ness,^[2] while Dabbs gives a figure of approximately 21,200 rifles.^[5] On the other hand, Harriman gives a figure of roughly 19,000 rifles produced in total.^[4]

Some rifles were used during the Battle of Leyte, though significant Japanese airborne operations ceased by the time the Type 2 entered production.^[2] Many, if not, most of the surviving TERA rifles today were captured by American forces in Leyte.^[5]

The Type 100 was modified from the Type 99 rifle.^[6] The rifle features an interrupted screw between the barrel and the receiver, allowing both parts to be joined and separated by a 90° turn. The bolt handle was also detachable.^[2] The broken-down rifle could be carried in bags strapped to the paratrooper's legs.^[4] The rifle was not put into mass production due the locking mechanism being deemed as inadequate.^[1]

The Nagoya arsenal built a few hundred rifles for the IJA and IJN airborne forces.^[2] According to Harriman, approximately 500 rifles were made in total.^[4]

A Type 38 carbine chambered for the 6.5×50mmSR Arisaka round with a hinged buttstock that could be folded behind the trigger guard,^[1][2] it could be easily readied for action at the drop zone.^[4] It was insufficiently robust enough for service and the IJA desired a 7.7 mm caliber rifle, resulting in the Type 1 being rejected.^[1] According to McCollum, the buttstocks had a tendency to wobble around while the hinge stud and wing nut used to keep the buttstock in place had a tendency of getting snagged on other things, damaging the locking system.^[3]

Around 500 rifles were made in total according to Harriman.^[4]

Similar to the Type 100 rifle, the barrel and receiver are joined together by a tapered wedge instead of the interrupted screw.^[2] The paratrooper used a folding wire ring to tighten the wedge lock. A detachable bolt handle and folding bayonet were tested, but ultimately rejected.^[4] Most rifles were fitted with the anti-aircraft rear sights of the Type 99 rifle, despite their questionable effectiveness.^[5]

The Type 2 was carried broken-down either in a canvas chest bag or with each halves in two leg bags. These were lowered on a short rope after the parachute opened.^[1]

• Harriman, Bill (2019). The Arisaka Rifle. Bloomsbury Publishing. ISBN 978-1-4728-1613-9.
• Ness, Leland (2014). Rikugun: Volume 2 - Weapons of the Imperial Japanese Army & Navy Ground Forces. Helion. ISBN 978-1-912174-58-4.
• Rottman, Gordon L. (2013). The Big Book of Gun Trivia: Everything you want to know, don't want to know, and don't know you need to know. Bloomsbury Publishing. ISBN 978-1-78200-950-4.
• Voigt, Don (2010). The Japanese Type 99 Arisaka Rifle. Eva, AL: Lodestone Publications. ISBN 978-0-9801826-8-2.

• Nambu World: Arisaka Type 2 Paratroop Rifle
• Media related to TERA rifle at Wikimedia Commons