575 rifles were donated to the Argentine Army to help test the rifle it was effectively used in the 2014 raid on the Collivadino Cartel in which it proved accurate and performed just aswell as the M-16 but it also proved more reliable due to the Tungsten Carbide lined barrel and Osmium lined internals.The K-16A2 is an interim design to be a place holder until the K-16A3 rifle is ready to be equipped to units. It is a improved K-16A1 with a new handgaurd, pistol grip and when it is issued it comes with a ACOG scope (advanced combat optical gunsight) and a mount to attack it to the carrying handle and a OKC-3s bayonet. 132 have been sold to the Argentine Navy and 213 were sold to the Argentine Army to augment there existing stock of K-16A1s.
The K-16A2c is a shortened K-16A2 it has all the same fetures except for a LE extendable stock and a 11.5in barrel. It also can mount the ACOG in a manner similar to the K-16A2 but it is not issued with an ACOG scope. 214 have been sold to the Argentine Airforce.
The K-16A3 is a newly designed rifle. It is erronously believed by many to be a improved K-16A2. However it has a new upper reciever. It also features a magpul grip, magazine, handguard and rear sight. It is set to replace all K-16A1's and K-16A2's in service with Argentine Army sometime in 2015. The Argentine Navy has not stated if it will be purchasing it.The K-16A3c is a carbine variant of the K-16A3 it features a shorter barrel, handguard and stock. It is slated to replace all K-16A2c's in service with the Argentine Airforce and 243 will be supllied to the Argentine Army sometime in 2015.
The K-16A4 is the latest in the series and improves upon the K-16A3 in many areas such as the implementation of more rails and the ability to be converted into the K-16A4c in a matter of minutes and the ability to mount an M203 grenade launcher without the need to change handguards.
The K-16A4c is the carbine variant of the K-16A4. It also has a 74% parts commonality. 80 have been issued to the DEA and ATF and 216 have been issued to Korigidorian Border Patrol.