Tuesday, May 05, 2015

How the QBZ-95 bullpup’s action works

by Timothy Yan, Original article on The Firearms Blog


The Chinese QBZ-95 bullpup has been in service for two decades and due to its sheer production, over 1.65 million so far, it will be the most prolific bullpup ever built. I did a detailed write-up on the QBZ-95 for Guns & Ammo SIP in 2006. Since then, that article has been used by many writers and researchers as reference. However, there’s still some confusion and misunderstanding on the QBZ-95’s inner workings. I hope this will help clarify the matter.

The QBZ-95 is one of the four post-World War II military rifle designs that use a striker-firing mechanism. The other 3 in chronologic order are: the Czech Vz 58, the Japanese Type 64, the Russian AS and VSS twins. Unlike the rotating hammer firing mechanism found on the majority of the modern rifles, a striker-fired rifle uses either a spring-loaded firing pin or a linear hammer to fire the chambered cartridge.
The spring-loaded firing pin type is common in the majority of bolt-action rifles and modern striker-fire pistols such as the Glock. The linear hammer type is used by most striker-firing selective fire rifles. This particular type of striker-firing system has a spring-loaded hammer piece that reciprocates forward and backward in the receiver.

The Czech Vz 58 was based on an early post-WWII indigenous select-fire full-caliber rifle design but it was redesigned to chamber the Russian M43 7.62x39mm cartridge. The Vz 58 was developed in 1958 and it is still in service with the Czech and Slovakian militaries. Its action uses a Walther style dropping block locking system with a short-stroke gas system. The Vz 58’s linear hammer type striker-firing system was the main inspiration for the trigger and striker design of the QBZ-95. Although, the QBZ-95’s striker design is conspicuously different than that of the Vz 58’s.
The Japanese Type 64 was developed in 1964 and chambers the 7.62x51mm full power round, while it normally uses a reduced power version of the 7.62x51mm. The Type 64 is still in limited service with the JSDF. Design wise, the Type 64 uses a short-stroke gas system with a tilting bolt lock action.
The Russian AS special purpose rifle was developed in the late 1980s. Its suppressed VSS twin went into service about the same time as the QBZ-95. Both the AS and VSS are chambered in the Russian 9x39mm special purpose cartridge. The striker and trigger part of both Russian weapons are very similar to that of the Czech Vz 58, just smaller in size. The Russian weapons use long-stroke gas system and an AR-15 style multi-lug rotating bolt.

The following animation from CCTV shows how the QBZ-95’s action works:
1) – After the 5.8x42mm cartridge is fired, the propellant gas passes through the gas port at front of the barrel (in light blue) and drives back the short-stroke gas piston system (in dark green).
2) – The long extension of the bolt carrier (in brown) receives a tap from the short-stroke gas piston while the whole unit starts traveling back. The gas piston spring (in green & white) returns the short-stroke gas piston.
3) – After a short travel, the cam track in the bolt carrier turns and unlocks the 3-lug bolt (in red). The empty cartridge case (in green) is extracted then ejected out of the weapon by a receiver mounted solid ejector.
4) – While the bolt carrier group (in brown and red) is moving back, it also pushes back the striker (in dark blue) along and compresses the striker spring. The reciprocating components come to a soft stop without hitting a solid surface with the help of a recoil buffer (in purple).
5) – The bolt carrier group (in brown and red) starts to travel forward again from spring pressure of the main spring. The striker (in blue) and striker spring is being held back by the sear in the trigger mechanism.
6) – The bolt (in red) strips a new 5.8x42mm round from the magazine and chambers it. The forward moving bolt carrier (in brown) turns the bolt (in red) to engage its 3 locking lugs into the locking slots on the trunnion. The weapon is read to fire.
7) – By pressing on the trigger (in yellow), the connected linkage (in white) pulls down the sear in the trigger mechanism and releases the striker (in dark blue). The striker impacts on the firing pin and fires the chambered 5.8x42mm cartridge. The action cycle repeats again.
The only changes in the latest QBZ 95-1 variant is the redesign of the recoil buffer (in purple) to use a coil spring with a rotating movement, and a new trigger mechanism that moves the selector forward and above the pistol grip. The fixed forward grip that makes up the trigger guard on the original is also replaced by a simple round trigger guard on the later models. Plus, the QBZ 95-1 barrel has a faster twist rate.
Unlike the relatively simple looking linear hammers on the Vz 58 and AS/VSS, the QBZ-95’s striker piece has a very complex shape. The striker spring arrangement is also very different. Instead of having two parallel springs, on the QBZ-95, the main spring and the striker spring are in-line and uses the same spring guide rod.

Since the end of the Cold War, modern combat rifles are being produced in much smaller numbers. I estimate that the Arsenal 276 and Arsenal 256 will still need to make at least 5 million copies of the updated QBZ-95 variants just for replacing all the old Type 81, QBZ-56C and the worn out initial QBZ-95 model in the Chinese service. The Israeli Tavor family (includes the newer X95) of bullpups will get adapted by more countries around the world, but just in the total production numbers alone, the Chinese QBZ-95 will outnumber all other bullpup military rifles combined.

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