SR1 is a balanced action rifle made by Kalashnikov Concern for the competition shooting market. We have earlier reported about this rifle which was shown during the Arms & Hunting 2017 exhibition. A couple of days ago, Kalashnikov Media released a video showing the pre-production prototype and revealing more details about this gun.
The balanced action system utilizes a counterweight of the same mass as the bolt carrier group, linked to the latter and moving in the opposite direction. This system proved to provide a better controllability in full auto fire especially with the SCHV (Small Caliber, High Velocity) cartridges such as the 5.56x45mm or 5.45x39mm. For a typical civilian firearm with no full auto fire capability, the advantages of the balanced action mechanism are minimal. However, competition shooters can gain benefits from the balanced action because they are shooting the semi-auto firearms so fast that a more controllable mechanism can really make a difference.
The SR1 rifle is chambered in .223 Remington. It has an AR-15 style magazine well which, according to Kalashnikov Concern, can take any AR-15 magazine. Controls of this firearm are different from those seen on ordinary AK rifles. The round knurled button on the receiver (see the image below) is a cross bolt safety. The rectangular serrated button in the middle is the magazine release button and the paddle at the bottom is the bolt catch/release. The magazine release, bolt catch and the charging handle are ambidextrous.