BENELLI M4 18.5" PISTOL GRIP - OD Green

The A.R.G.O. system is a unique, short-stroke, dual-piston design developed for the M4 Tactical shotgun in 1998 for the U.S. Marine Corps. It was later adopted as the U.S. Joint Services combat shotgun—and remains so today.

The gas port is located just forward of the chamber, where the gases are hotter and cleaner. This results in less fouling and more reliable cycling.

Pistons push directly against the bolt, for fast operation and minimum vibration.

There are no connecting linkages or heavy action bars under the forend, which add weight.