Shotguns have been used by American law enforcement since the earliest days of the country, but the shotgun came only into its own as a military small arm during World War I, when American “doughboys” went to France equipped with modified Winchester Model 1897 “trench guns.” For law enforcement, the shotgun remains a very effective weapon despite a trend toward rifle caliber carbines. The shotgun is much more flexible than rifles, offering a tremendous variety of ammunition from less-lethal to slugs to lock-busters to buckshot.
The U.S. military’s most recent tactical shotgun is the Benelli M4, officially adopted as the M1014, and now replacing the Mossberg M590 and other slide-action tactical shotguns in U.S. inventory. For law enforcement sales, the M1014 has been designated M4.
Selection of the M1014 began with a U.S. Marine Corps requirement for a “combat shotgun” that was established in the early 1990s. The requirement was later revised to include the entire U.S. military, with the Marine Corps retaining program management. The U.S. military M4 project was managed by Heckler & Koch, while the gun itself was developed by Benelli.
The M4 is a semiautomatic, gas-operated, tubular magazine-fed shotgun. The bolt assembly is similar to other Benelli models, with a bolt carrier and rotating two-lug bolt that locks into a barrel extension. The shotgun’s gas operation system incorporates a novel design that Benelli calls Auto-Regulating Gas Operation, or “ARGO.” The ARGO system uses two gas ports and tappet-type pistons that ride in short tubes beneath the gun’s barrel just forward of the receiver. The pistons impinge directly against the face of the bolt carrier to cycle the gun each time a round is fired.
The system is unaffected by fouling, requires little or no maintenance, and functions reliably with all types of standard shotgun ammunition from low brass target loads to 2 ¾-inch magnum rounds. We verified this in testing, although we did have failures to cycle with one type of low recoil buckshot, which the military specification did not require the gun to handle, but which might be used by some agencies.
The ARGO gas system is a simple design that we estimate will be extremely reliable in service if our evaluation of the gun is any indication. The ARGO system cycles the M4 just as rapidly as its recoil-operated brethren. Benelli shotguns are noted for rapid cycling and the M4 is no exception. The M4 magazine can be emptied with almost machine gun speed while maintaining full control.
Military testing has proven that the M1014 will reliably function for at least 25,000 rounds of standard ammunition without replacing any major components. We informally fired the M4 using ammunition ranging from low-brass target loads, tactical reduced recoil through full-power magnum 2 ¾-inch shotgun ammunition, and found that the M4 functioned flawlessly, regardless of the type of ammunition we used, with the exception of Winchester low recoil buckshot.
Our formal evaluation consisted only of ammunition offered for LE use by the manufacturers. The M4 will not cycle less-lethal ammunition such as rubber buckshot, “bean bags,” or any other similar less-lethal ammunition. This is not a criticism, as there was no military requirement for the shotgun to function semiautomatically with these types of ammunition. The only military requirement was that the gun be capable of manual cycling to operate with less-lethal or reduced recoil ammunition.
The M4 is a modular design so the user can quickly exchange major components, including barrel, buttstock and forearm to meet changing tactical requirements. In its basic configuration with collapsible buttstock, the M4 gives the appearance that it would be awkward to handle, but this is not so. We found the shotgun to be very well-balanced and comfortable to fire in all configurations.
The overall design coupled with the ARGO gas system has the effect of reducing felt recoil and muzzle rise regardless of the type of ammunition used or stock configuration. Available buttstock configurations are collapsible with pistol grip, pistol grip only and semi-pistol grip. Changing the M4 into any of its various configurations was easily understood and simply accomplished without written instructions.
The M4 field strips quickly and easily without tools, unless one counts the charging handle, which is withdrawn from the bolt carrier and used to remove the trigger group and disassemble the gas system for cleaning. Disassembly and assembly for reconfiguration or cleaning is straightforward and can be performed without tools in a matter of a few seconds. External finish is heavy phosphate black on steel parts and hard anodizing on aluminum components.
Standard M4 sights are of the “ghost ring” type with a large rear aperture sight and blade front sight for quick target acquisition. Open sights are adjustable for windage and elevation using the rim of a shell. The front sight is fixed in place with a hex nut and can be replaced with a tritium unit if desired. The gun is fitted with a semi-fixed MIL-STD-1913 rail on top of the receiver for optical sights. The rail is held in place with locking screws and can be removed if desired.
The M4’s 18.5-inch barrel has optional removable choke tubes to accommodate virtually any type of ammunition or tactical condition. A 14-inch barrel is also optionally available. Magazine capacity varies with barrel length. The M4 with standard 18.5-inch barrel will accommodate seven shells (six in the magazine, plus one in the chamber), while the 14-inch barrel reduces total magazine capacity to six (five plus one) 2 ¾-inch shells or five (four plus one) three-inch shells. Overall length of the M4 is 40 inches with stock extended, 35 inches with stock collapsed, and 30 inches with short barrel and stock collapsed.
We should note that there are two significant differences between the law enforcement M4 shotguns and the civilian “commemorative” version that has recently been reported upon in other periodicals.
First, the magazine capacity of the civilian version is restricted to five rounds. Although the magazine tube is the same apparent overall length as the M4 LE version, there are what appears to be “fins” a few inches back from the muzzle end of the tube. These are a cosmetic part of a magazine constriction that blocks the tube and limits capacity to five rounds.
Second, although the civilian version’s stock appears to be of the collapsible type, it actually isn’t. The recoil spring tube and buttstock have been modified so the stock cannot be fully collapsed.
Ammunition can readily be changed from one type to another as the tactical situation changes. The shell in the chamber can be ejected without feeding a new round onto the elevator by simply pulling the charging handle to the rear. A fresh shell can then simply be dropped onto the elevator, the bolt release pressed, and the new round chambered.
If the user wishes to discard the chambered round and bring up a new shell from the magazine, he presses the small release button located on the receiver bottom near the trigger guard and pulls the charging handle, thus ejecting the chambered round and feeding a fresh one from the magazine.
The shell release button is shaped differently from the safety and must be pressed in a different direction for actuation. There is thus little possibility of confusing the two. Tactical reloads can be accomplished at any time during a break in firing by simply “topping off” the magazine through the loading port.
Our test of the M4 revealed that it is an outstanding semiautomatic tactical shotgun. The gun is very well-balanced. It handled and pointed well, despite the awkward appearance of the collapsible buttstock. With the semi-pistol grip or full-pistol grip stock installed, the gun handles even better, but we suspect that most operators will prefer the sliding stock, as it makes entry and exit from cruisers less cumbersome, not to mention the fact it takes up less space in the officer’s already crowded “office.”
The sliding stock is easily removed by pressing a release, turning 90 degrees, and pulling the stock off to the rear, leaving the pistol grip in place. The collapsible stock configuration thus provides the greatest degree of tactical flexibility. The cross bolt safety is located at the rear of the trigger guard. It has an oversized and uniquely shaped head that is difficult to mistake for anything else, even if the user is wearing gloves, and can be reversed for left-handed users. The example we tested was equipped with a modified choke.
We tested buckshot at 10 and 25 yards and slugs at 25 and 50 yards using Federal, PMC, Remington, Winchester and Wolf ammunition. The only failures were with Winchester Ranger low recoil buckshot, which failed to cycle the M4. Benelli informs us that this is not spec ammo for the M4 and Winchester informed us ahead of time that this round would probably not cycle the M4.
That said, all that was necessary to cycle the gun was to simply pull the charging handle to the rear. The M4 shot essentially to point of aim, placing all slugs and buckshot into the center of mass of DEA “Q” Target silhouettes at all test distances.
What didn’t we like about the M4? Not much, although we still generally prefer a slide action gun for tactical work, since even the best semiautomatic will not function with the full spectrum of tactical ammunition now available to military and law enforcement agencies. Manually cycling any semiautomatic shotgun to operate the gun with less-lethal ammunition can be somewhat cumbersome due to having to pull the charging handle for each shot and the necessity to remove a hand from the gun to accomplish the task.
This, however, is a subjective judgment and must be balanced against the fact that a gas-operated semiautomatic shotgun like the M4 greatly reduces felt recoil, thereby enhancing accuracy, which are decided benefits.
In addition, for those with limited shotgun experience, a semiautomatic provides faster target engagement and eliminates the possibility of “short stroking,” which is inherent in slide action guns. Given the influx of smaller framed officers into law enforcement, we believe that the semiautomatic tactical shotgun will gradually replace slide action guns due to the advantages they offer to the average law enforcement officer.
Manually cycling a semiautomatic shotgun using less-lethal and similar ammunition can be overcome by training. In the final analysis, users will have to judge for themselves which type of shotgun best suits their agencies’ requirements.
Overall, Benelli’s M4 offers the organization desiring a semiautomatic tactical shotgun what is almost certainly the best such shotgun available today. It is reliable, lightweight, well-balanced and has outstanding ergonomics.
The M4 can be arranged into virtually any tactical configuration imaginable, from entry gun with 14-inch barrel to full-length barrel. The MIL-STD-1913 rail allows employment of any standard optic or night vision device. Any agency that has a requirement for a semiautomatic tactical shotgun would do well to follow the U.S. military’s lead and look very closely at the Benelli M4.
Charlie Cutshaw is a small arms, ammunition and infantry weapons editor for Jane’s Defense Information. He served as an Army infantry, ammunition and intelligence officer prior to retiring in 1996. His military assignments included a tour of duty in Vietnam as an advisor. He currently lives in Alabama, where he is a full-time writer and reserve officer. http://www.Benelliusa.com