The AK-12 rifle, slated to be adopted by the Russian Army in some capacity late this year, has been delayed in production until 2016. According to Russian news media sources, the rifle will undergo a series of improvements of an unspecified type. From military-informant.com:

Latest AK-12 Russian military will have only one year – Adopt the machine is delayed due to the need to refine its design, according to “Rossiyskaya Gazeta”. 

According to the deputy chairman of the board of the Military-Industrial Commission Oleg Bochkarev, in 2015 will only begin troop operation, and the first production batch of AK-12, you should reap the army only a year later.

However, Bochkarev assured that the machine has received preliminary tests on non-critical comments and shortly after the improvements, it tests continue.”

It’s unclear whether the new Kalashnikov is being delayed because problems have cropped up in testing, or whether further improvements are being incorporated into the rifle. The AK-12 brings the Kalashnikov rifle family essentially up to par with Western developments like the M4 and SCAR, so there’s a nontrivial chance that Russian engineers are seeking to include improvements that could make it more competitive than those Western platforms, or even that they may be seeking to leapfrog the Western rifle designs in capability.

The Military-Informant article mentions that the AK-12 will be chambered for 6.5 Grendel; this may not be the case, as there exists a different Russian caliber also designated 6.5×39 that may be the fifth chambering of the rifle mentioned in certain literature, after the 5.45×39, 7.62×39, 5.56×45, and 7.62x51mm. As far as this author knows, all mentions of the 6.5 Grendel specifically as the fifth chambering cite a source that is no longer available for verification.