From The TimeSplitters Wiki

The Soviet Rifle is an assault rifle that greatly resembles the real-life FN FAL(which ironically enough was a NATO weapon). It has the lowest rate of fire of all the automatics in TimeSplitters Future Perfect, but it more than makes up for it with its incredible power per shot. It has a magazine size of 30, and you can carry up to 170 bullets at a time.

It has only appeared in TimeSplitters Future Perfect.