Benelli’s gas operating mechanism is famed for its reliability, strength and safety and guarantees accurate shooting over the years – as approved by the Marines.Simplicity, sturdiness, original and ingenious design are thedistinguishing features of the patented A.R.G.O. Auto RegulatingGas Operated system, the gas-operated mechanism at the heartof the Argo and M4 models.

Consisting of a gas operation unitcontaining a short-stroke piston, A.R.G.O. is located under the barrel,near the firing chamber, in order to exploit the hotter gasses andgreater pressure. The gasses flowing from the barrel expand (in thegas collection cylinder) and rapidly accelerate the piston stroke,which simultaneously impacts with the bolt follower pins transmittingsufficient thrust to the bolt to send it backwards. It is self-cleaningbecause the position of the gas operation unit means that it works with gasses that are still hot and with relatively high pressures;in this way, the operation will always be safe with less build upof deposits. It is self-regulating because the gas operation valve actsas a regulator that expels excess gasses during firing.The greaterthe volume of gas flowing from the barrel, the quicker the pin valveopens and allows it to escape, in this way reducing the pressureinside the gas operation unitSelf-cleaning and self-regulating, A.R.G.O. guarantees firing precision, reliability, durability and confirms the technological superiority of Benelli.