STV Rifles

The STV, short for Súng trường Tấn công, Việt Nam" (translated: Assault Rifles, Vietnam)" is a family of assault rifles made in Vietnam. They are all produced at the Z111 Factory. Currently, all of the rifles are chambered in 7.62x39mm.
As of 2021, the STV-215 and the STV-380 are the standard issued rifles for the People's Army of Vietnam.
History.
In 2014, the People's Army of Vietnam adopted the IWI Galil ACE 31/32 as the standard issue rifle. This includes a license to manufacture them locally at the Z111 Factory. The factory immediately began modifying the IWI Galil ACE to better suit the local terrain and climate, and also including more Kalashnikov parts. This was done to improve familiarity and smoothen the transition from older AK-47 and AKM assault rifles, which were used by Vietnamese soldiers. 
The modification process was a fusion of the STL-1A and the Galil ACE, this resulted in a prototype rifle named the GK1 and the GK3. Although since then, not much information has been released about the prototypes. It is very likely the current STV rifles were a result of further development and modifications of the GK1 and GK3 prototypes.
In 2019, the Z111 Factory revealed two new rifles. Designated the STV-215 and the STV-380, the number at the end would indicate the length of the barrels. These two new rifles would be replacing the IWI Galil ACE 31/32 as the standard issued rifle for the People's Army of Vietnam.
In 2020, two new variants of the STV rifles were revealed. These rifles were designated as the STV-410 and the STV-416. Compared to the previous two variants, the new ones would adopt more AK parts into the guns. Currently, the STV-215 and STV-380 remain as the standard issued rifles.
Design.
Overall, all of the variants are generally similar and are mainly built off of the IWI Galil ACE's milled receiver. They are all chambered in 7.62x39mm and can use any standard AK-47/AKM magazines.
The rifles all have the charging handle located on the right side, which is the same for all IWI Galil ACEs manufactured in Vietnam. However, the selective-fire mechanism uses a traditional AK-based mechanism. The handguards and pistol grips are made of polymer and all of the rifles have a folding stock. A bird-cage muzzle brake is included on all rifles.
As the handguards and receiver include a picatinny rail on top, attachments can be mounted on such as Telescopic sights, Red Dot sights, or Holographic sights. The rear sight is located at the rear of the gun. The only exception being the STV-416, which does not include any picatinny rails. 
The STV-215 and STV-380 have an additional picatinny rail located on the bottom of the handguard, commonly used for a foregrip/bipod, laser, or flashlight attachment. The pistol grip for these two are built-in to the body of the rifle. The folding stock is similar to the FN FAL PARA and includes a rubber recoil pad. These two variants also share the front-sight and gas block similar to the ones found on the IWI Galil ACEs. 
The STV-410 and STV-416 both lack a picatinny rail on the bottom of the handguard. Instead, they include a mount for an underbarrel grenade launcher. They also have a slightly different mag well and trigger rim that resembles the style of the AK. The pistol grip for these two variants are also independent of the body and are also based on the AK. These two variants use a folding Polymer AK stock instead of the FN FAL styled stocks used by the STV-215 and STV-380. The front-sight and gas block on these two variants are different from each other.
Variants.
STV-215.
The STV-215 is the carbine version of the STV-380. It is used alongside the STV-380 as one of the standard issued rifles for the People's Army of Vietnam. It is similar to the STV-380 in all aspects, except the barrel length being 215mm. 
STV-380.
The STV-380 is one of the standard issued assault rifles for the People's Army of Vietnam. It's barrel length is 380mm. It has a foldable stock similar to the FN FAL PARA. 
STV-410.
The STV-410 is an assault rifle with a barrel length is 410mm. The build of the rifle overall resembles an AK-15. The handguard's picatinny rail is slightly extended to cover the entirety of the handguard. The front sight and gas block are also similar to the ones found on the AK-12/15.
STV-416.
The STV-416 is an assault rifle, which resembles an AK-103. The rifle is the only variant that does not include any picatinny rails. Instead, it includes a side-mount for sights and a mount on the handguard for a grenade launcher. The rear-sight is moved up to the rear of the handguard. The front-sight and gas block are similar to the ones found AK-103.