Pump-action operation is employed when shooting less powerful shells, such as rubber bullets, that do not generate enough recoil to operate the semi-automatic mechanism. Conversely, the semi-automatic mode can be employed with more powerful shells, absorbing some of the recoil. Switching between the two modes is done by manipulating the ring located at the front of the forend grip. The Benelli M3 also features a removable stock allowing the user to choose one of two styles, the traditional shotgun stock or a stock with a pistol grip. The Benelli M3 is an updated version of the Benelli M1 shotgun. The M3 uses the same inertia recoil semi-automatic system as the earlier Benelli M1, but adds another Benelli-patented feature, which allows the shooter to lock the semi-automatic action and switch to the manually operated pump-action mode and back in the matter of seconds. The action type switch is located at the forward end of the forearm, and is formed as an annular knurled ring. Rotation of this ring either engages the action rods of the pump system and locks the semi-automatic recoil system, or disengages the action bars, locks the forearm and allows the inertia recoil system to operate the action automatically. This greatly improves the versatility of the shotgun, allowing it to fire low-powered ammunition in the manually operated pump action mode, and to fire full power combat loads with slugs or buckshot in rapid semi-automatic mode. An underbarrel tubular magazine usually holds 8 rounds for police or military versions, or less in some civilian models. The M3 Super 90 is available with various barrel lengths and stock options, with fixed butt and semi-pistol or pistol grips, or with top-folding butts and pistol grips. Sight options include shotgun-type open sights, rifle type open sights, ghost ring sights and various mounts for reflex or low magnification telescope sights and tactical flashlights and laser pointers.
Variants
The Benelli M3 comes in several variations, most notably the M3 Super 90, which features a smaller body. There is also a shorter version, which is easier to transport, used by law enforcement officers. While other Benelli self-loading shotguns have the recoil spring inside a tube in butt-stock, in the M3 the recoil spring is placed around the magazine tube. This is an interesting feature for weapon modification, since other shotguns attach the butt-stock to the recoil spring tube. The M3 has a dummy tube just for stock attachment. Benelli's M3T is an OEM variant, where the butt-stock and dummy tube have been replaced with a pistol grip and up-folding skeleton butt-stock. Benelli's SuperNova pump-shotgun and MR1 self-loading rifle have similar butt-stock attachment to the M3, so this adds two new butt-stock options to M3. The M3 butt-stock and dummy rod can be replaced with a "Benelli SuperNova Tactical Collapsible Stock". The collapsible stock allows 5-position draw length adjustment, so a shooter can compensate the effects of thick winter clothes or body armor by adjusting the stock length. The required spare parts are: Adjustment rod, pistol grip and collapsible butt-stock. A rare modification is to replace the M3 butt-stock and dummy rod with a "Benelli SuperNova Handle Grip". The "handle grip" is just the pistol grip attached to the receiver with a screw.