Boo

Of course it looks like an ASK-74U just about all the soviet weapons are based on the AK platform with modifications. The only truly unique one in the game is the SVD/SVU. Even the Bizon(Zubr in game) is based on the AK. RPK as well.

Its not unusual though if you find something that works and have all the tooling and expertise in making it, why mess with it unless something offers a significant bump in performance? That's the same reason the US has kept the AR-10 platform as its standard for so long.