Best Benelli Semi-Auto Shotgun: M2 vs M3 vs M4
Looking for a Benelli semi-auto shotgun? We go over the differences between the M2, M3, and M4 variants. By the end, you'll know which one is best for you.
USMC Veteran. Concealed Carry & NRA Pistol Instructor. 3-Gun Competitor. Career firearms writer
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Italian gun makers make lots of cool guns, but for some reason, they excel at shotguns.
From beautiful double-barreled clay guns to tactical shotguns, the Italians know how to make good guns.
Beretta and Benelli make the best combat shotguns by far.
This isn’t surprising since Beretta owns Benelli as well as Franchi and Stoeger, giving them a quality control chokehold over the Italian shotgun market.
Benelli is mostly known for its semi-auto designs, specifically the M series. The M1/M2, the M3, and M4 are all fascinating and revolutionary designs.
What makes them so great? What makes them so different?
Well, I’m glad you asked because we are going to be talking about it in-depth today. By the end, you'll know which one might be the best one for you.
The HK Beginnings
The Benelli inertia recoil system is actually best described as the HK recoil system. However, the system was created by Franchi, who designed and built the Heckler and Koch shotguns under contract.
To make things even more interesting, Franchi is owned by Beretta, who also owns Benelli.
The HK 512 is a cool shotgun, but exceedingly rare. This gun was designed for tactical use, and apparently, the GSG 9 adopted them, as well as special police and military units in Spain, Portugal, and Austria.
HK and Benelli seemingly had a great relationship, and HK imported and marked Benelli shotguns for import for quite some time.
It’s not uncommon to find Benelli M1, M2, and M3 models with HK markings.
Now that Beretta owns Benelli, though, the importation is easily taken care of by the massive Italian gunmaker.
Inertia vs. Gas
Benelli made their bread and butter on their rotating bolt inertia-driven designs. These shotguns, like the M1, M2, and M3, proved to be reliable, fast cycling, and clean.
Better yet, the system proved to be more reliable and simpler to produce than the old Browning long recoil design used in guns like the Browning A5.
Benelli only stepped out of the inertia-driven box to produce the famed M4, which became the Marine Corps M1014 Joint Service Shotgun.
The M4 is Benelli’s gas-powered gun that uses the ARGO system.
There are pros and cons to both systems when it comes to semi-auto shotguns.
Inertia-Driven
The inertia system works in a way that’s simple but complicated to explain.
Benelli didn’t invent the inertia system, a man named Carl Axel Theodor Sjogren did in 1900. He created about 5,000 semi-auto inertia-driven shotguns and was moderately successful.
Benelli uses the same principle but a simpler and more robust recoil system. Inside the bolt is a very strong spring called the inertia spring. When the gun fires, it recoils, causing all the fixed parts of the gun to move rearward.
The bolt and inertia spring are basically free-floating and therefore stay put initially.
The difference in motion between the bolt and spring and the rest of the gun causes this super-strong spring to compress between the rear of the bolt and the bolt head.
After the shot leaves the barrel, the recoil force begins to dissipate. The spring is released because the spring is so strong the power of it rebounding causes the bolt body to unlock the rotating bolt head and throw the bolt rearwards.
This ejects the spent shell and recocks the gun’s hammer. The bolt then meets a recoil spring that sends the bolt back forward, and on its way, it picks up the next round and locks the bolt into the barrel.
This all happens faster than you can possibly perceive.
Why Go Inertia?
Shotguns are best when they are lightweight and quick to action, and if you want a light shotgun that swings easily and quickly, then inertia guns are for you.
Inertia guns like the M2 are more than a pound lighter than the M4 when you compare similar models.
Inertia guns are great for waterfowling hunting and shooting clay birds because they are so dang light. Better yet, another reason to love inertia guns is how little maintenance they need.
There are no ports, and all gas is expelled out of the barrel. This means you can shoot and shoot and shoot, and your inertia gun will keep running like a clock.
The downsides to inertia guns are few but should be noted. First, they are sensitive to weight changes. When you change the weight of a gun, you change the way it recoils.
When a gun relies on recoil to operate, you have to be careful about weighing it down with optics and accessories.
Your average red dot and side-saddle aren’t going to mess it up, but I’m sure if you kept adding weight, you’d find the spot eventually.
Also, inertia guns tend to be a little rougher recoil-wise. Still better than a pump-action, but a little heartier than a gas-operated gun.
Gas Guns
The Benelli M4 doesn’t use a standard gas system but uses the ARGO system. This gas-powered system was created by Benelli for the Marine Corps. ARGO stands for Auto Regulating, Gas Operated.
The ARGO is a short-stroke, dual gas piston design. When the weapon is fired, gas is created by the exploding gun powder.
This gas propels the shot downrange, and a little is bled off to operate the shotgun.
A gas port feeds gas to the pistons, which cycles rearward and has direct contact with the bolt. They throw the bolt rearward and eject the fired round and cock the hammer.
In the end, it meets a recoil spring and is sent back forward, loading the next round and returning to battery.
Going Gas Powered
Gas-powered guns offer less recoil and a fast cycling design. You can get several shots on target very quickly with minimal effort. Gas guns also work with a lot of different loads.
This means lighter loads are more likely to cycle with fewer issues. You are also going to get less recoil that gets noticeably more comfortable with heavy-hitting slugs.
The ARGO system, in particular, does an excellent job of reducing recoil.
Also, these guns can be weighed down quite a bit and will keep running. Add on your favorite red dot, side saddle, flashlight, sling, and the kitchen sink, and the gun will still run.
The downsides are that gas guns can be heavier. Benelli does a good job of eliminating heavy linkages and other parts to reduce weight, but even their efforts give you an ultimately heavier gun.
Also, a gas gun requires more maintenance than an inertia gun. Again, Benelli’s ARGO system is much cleaner than most gas systems and requires less maintenance than most gas guns.
However, setting a Benelli M2 beside a Benelli M4 and I’m betting the Benelli M4 chokes first.
It’s likely not going to choke until you are into the thousands of rounds, but it will eventually.
M2 vs. M3 vs. M4
Now that we know the biggest differences between the different Benelli operating systems we can discuss the actual guns.
This means we are talking about the M2, M3, and M4. Now you may be asking what about the M1?
The M1 is still a good gun, and if you find a cheap one, snatch it up. However, the M2 has replaced the M1 as their primary inertia-driven semi-auto shotgun meaning the M1 is no longer produced by Benelli.
The M2
This series is likely the most popular of the Benelli series of shotguns. The M2 also comes in the widest variety of configurations.
It comes in the tactical model we all know and love, but also comes in a Field model, a Field Rifle Slug gun, a 3-Gun model, a Turkey Performance shop, and a Waterfowl model.
Within all these models, you get a wide variety of different finishes and 20-gauge and 12-gauge calibers. The M2 is inertia-driven and a fantastic shotgun.
They are quite popular for 3-Gun in a variety of configurations. And it was the shotgun of choice for John Wick in John Wick 3.
Not to mention, the Benelli pro team commonly cleans up the competition.
The Tactical model has three different configurations that include the standard with a pistol grip, the Comfortech with a recoil-reducing stock, and a standard model with a straight stock.
You can also choose between open rifle sights and ghost ring sights.
The Benelli M2 is also the lightest of the Benelli shotguns and weighs only 6.7 pounds.
I believe shotguns should be nice and lightweight, and they are best when they are quick on target. Benelli hits it on the head with the M2 certainly gives shooters that advantage.
This series is also the most affordable and common of the Benelli shotguns. But don't let price fool you. It's still massively popular, and the price isn’t a reflection of lower quality.
The M3
The Benelli M3 is my favorite shotgun of all time. It might be the most capable and versatile shotgun on the market. And it's one of the rare convertible shotguns.
A convertible shotgun is one that allows the user to swap between a semi-automatic action and a pump action.
The benefit of the M3’s system is that you can use any shotgun round on the market. The pump-action mode allows it to cycle low recoiling rounds that won’t cycle in a semi-auto action.
This includes less-lethal rounds, as well as breaching rounds, low recoiling birdshot, flare rounds, and more.
The M3 should best be thought of as a semi-auto shotgun with pump capability.
When it comes to being a fighting shotgun, the semi-auto mode should be the primary mode utilized. The pump action is reserved for those special rounds.
Also, if you gum the gun so bad it won’t function, then I guess pump-action could be handy. However, this is an inertia gun with a system almost identical to the M2, so it won’t gum up without outside influences.
The M3 only comes in a tactical configuration with a stock and pistol grip as well as ghost ring sights. This gun is most famously used in the film Heat, which is where I grew my affection for it.
The Benelli M3 also gets lots of military love overseas -- New Zealand, The UK, France, the Czech Republic, Canada, and many more use the weapon.
From a military and police perspective, the gun makes a lot of sense.
The Benelli M3 can be a little harder to find compared to the M2 and M4 and is right in the middle when it comes to price between the two. Also no optics rail.
What do you think of the M3? Give it a rating below.
The M4
Finally, we get an optic rail. The Benelli M4 is Benelli’s first gas gun, and it was purpose-built for the Marine Corps.
The reason Benelli went with a gas system is that the Marine Corps wanted the ability to toss on thermal and night vision optics.
The Benelli M4 is one of the cleanest running and most reliable gas-operated shotguns on the market. It’s the heaviest shotgun in Benelli’s lineup, but still only weighs 7.8 pounds.
Configurations vary between fixed stocks with pistol grips and standard stocks.
The sights and scope rail are identical to all guns. Its sights are very well done ghost ring sights while the standard anodized black is the most common the titanium Cerakoted H20 models and a desert camouflage model.
The M4 is a ton of fun to shoot and incredibly smooth shooing. Recoil is quite comfortable, and the gun runs everything from light to heavy loads without issue.
This includes reduced recoil Flitecontrol rounds.
The M4 is being used by the Marines, the LAPD, and the militaries of the UK, Australia, France, South Korea, and many more. It’s also the chosen weapon of John Wick in John Wick 2, and I think that bears mentioning.
Downside: it's also the most expensive of the Benelli shotguns. But it's an excellent weapon and worth the price from a heavy user perspective.
Want to know more about the M4? Check out our full review or watch the video review below.
Conclusion
You may consider the Beretta 1301 the best tactical shotgun, or maybe you hate semis and stick to pumps, but I bet you’ll also admit the Benellis are fine guns.
Even the Nova is a fantastic pump action with a forward-thinking design. Benelli just knows shotguns and knows them well.
We can’t say the same about semi-auto rifles, but they make a darn good shotgun.
What say, you fine folks? Like Benellis? Love a particular model? Let us know in the comments! For a ton more info about shotguns and the best loads to run, take a look at these articles also: