The latest version of Russia’s world-famous Kalashnikov assault rifle, the AK-12, has completed a set of preliminary tests, the weapons-making agency responsible for trials of the new gun said on Friday.

Last week, Dmitry Semizorov, head of the Tochmash state arms firm based near Moscow, said the AK-12 “has shown up a range of problems” and “a series of flaws.” He declined to elaborate on what the defects were, saying this was “the developer’s confidential information.”

The weapon was developed by Izhmash, the Izhevsk-based gun maker which has built Kalashnikov rifles since the 1950s.

Izhmash director Vladimir Zlobin said the initial testing was in fact designed to identify the AK-12’s faults and weak spots and fix them.

State acceptance trials for the weapon are due to begin at the start of 2013 and be completed by June or July of that year, Zlobin said. Series production is due to begin at the end of 2013.

Development of the AK-12 began in mid-2011. The new weapon retains the overall layout and features of the 5.45-mm caliber AK-74, in service with the Russian Army since the 1970s, but has minor modifications and ergonomic changes.

Zlobin has claimed that law enforcement agencies have shown strong interest in the new weapon, on which a range of firearms are to be produced including pistols, submachine guns and assault rifles for general military and special duties tasks.

Izhmash, and Izhmekh, another gun-maker, are to be amalgamated in a new state-controlled small-arms and light-weapons holding under the Kalashnikov brand, under a government plan to consolidate the industry, Deputy Prime Minister Dmitry Rogozin said earlier this month.