The gas-operated weapon was produced by the concerns of SAKO Ltd and Valmet to which over, examples were ultimately manufactured. This dramatically decreased the weight of the gun. During the following years, the state-owned Valmet company, the manufacturer of the Rk. Additionally the rifle can be adapted to use various optical sights i. The cylinder is utilized in the gas-based operation of the firing action, 'tapping' the barrel after each successive round is fired to reuse this high pressure in the next action.