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Airsoft Surgeon M870 Slug Shot
  • Manufacturer 
     Airsoft Surgeon
  • Model 
     M870 Slug Shot
  • Capacity 
  • Weight 
  • Power 
  • Power Source 
  • Blowback 
  • Hop-up 
  • Shooting Mode 
  • Construction 
     Metal + polymer


+Realism to The Extreme!
+Excellent build quality
+High power
+/- Ejecting shells


-Costly ammo
+/- Ejecting shells


Products like this are one more reason why Airsoft models can and should be taken seriously. Airsoft Surgeon shotguns adds to the selection from a fresh new angle, that has so far been left relatively unexplored.



Although shotguns have a worldwide history in almost all locations where firearms have been known and used, it can safely be said to be a very North-American weapon. Muskets and other early firearms regardless of origin had a smooth bore, and they used solid spherical bullets as well as a "shot" (small amount of pellets shot at the same time), but the term "shotgun" was first reportedly used in Kentucky as early as 1776. When barrel rifling was invented and became more common, and the barrel bore of said rifled weapons was reduced in size, the long group of firearms was separated into rifles and shotguns.

The development of shotguns continued alongside other innovations made in the firearms industry. A well known name for all small-arms enthousiasts, John Moses Browning, has a lot of innovations and inventions under his name. When it comes to shotguns, these include the first lever action shotgun (1887), the first pump-action shotgun (1893), and the first semiautomatic shotgun, the Auto-5 (1900). The latter remained in production for almost a hundred years, until 1998.


Despite being invented almost at the same time, law enforcement and military users still stick mostly to pump-action shotguns. They offer a more simple and robust construction that is cheaper to manufacture, and are insensitive to the power of the load. Most "less lethal" rounds such as bean bags and rubber bullets are fired with such a small load of gunpowder, that semiautomatic shotguns would malfunction or refuse to cycle at all.

The worldwide military usage of shotguns has been a dragon's back, going up and down as certainly as the world goes around. The limited range of shotguns make them less than ideal for longer ranges. On the other hand they have been proven worthy their weight in gold, when utilized to sweep trenches in the first world war, brush through the jungles of the Pacific in the second big fight, and in the dense bushes of Vietnam in the sixties. With shotgun-launched grenades in development to add to the already wide selection of ammunition, the shotgun is far from being an outdated weapon.

Original flavour! This is the first in the line of Airsoft Surgeon Slug Shot shotguns...
...then came the 18inch version...
...and with the addition of an Airsoft Surgeon Extended Mag Tube that provides an extra 3 rounds of storage.


Given their long history and wide reputation among real firearms, you would think shotguns are popular and common in airsoft as well. Actually, they are not. A lot of airsoft shotguns fire a single BB, which makes them no different in function from airsoft pistol and rifle models. Very close to something that actually works like a shotgun with good effect have been the 40 mm grenade launcher models.

Tokyo Marui did bring something new in the fields with the SPAS-12, that fires 3 BBs with a remarkably good range and decent spread as well. Still, it has been criticized for being hard to cock, and a lot of users ask for a more realistic loading action. You have to admit that with shotguns, just like revolvers, the shells are an important part of the "sense of wonder" and immersion into the game or simulation. With a rifle or pistol you simply change a magazine to reload, but with revolvers and shotguns the shells are manipulated by hand.

Maruzen took a step forward with their M870 and M1100 series shotguns, which use more realistic shells and shoot multiple BBs. From a gamer's point of view, the power is not satisfying, and the shells are undersized compared to real 12 gauge shells. These models also require a gas tank in the grip or stock to operate, which puts a limit to the firepower you have at hand, even if your belt, bandolieer and pouches are full of shells.

Some of CL's customised Tanaka M870's.
Clarence himself, with his creations.
The Tanaka M870 features realistic shell eject.


Not more than a couple of years ago, Tanaka released the most realistic airsoft shotgun to date, their replica of the famous Winchester 1897. With realistic sized shells with gas inside, and quite a a good power straight away, it combines the good features of airsoft shotguns in one package. The shotgun series, now expanded with the Remington M870, have metal receivers and outer barrels, and even the internals are very realistic in action! Of course there are key points in the design, which effectively prevent firing real shells or converting the model to do that.

All the good points aside, the shells are ABS plastic, and their tips have a tendency to get detached and lost easily. They also suffer from anything more powerful than HFC134a. In any case, "Airsoft Surgeon" Clarence Lai thought this was the near-perfect platform, on which to base his lineup of custom shotguns.

This is how you load a pump-action shotgun. Applicable to Tanaka Works, Airsoft Surgeon and various real models.

First things first, you need something in the chamber.
Open the action and feed one shell on the elevator through the ejection port.
The shell drops in the correct place automatically.


As with all his Airsoft Surgeon custom guns, Clarence thought first how to improve the platform that was good already. "The upgrade must be effective, or it isn't worth doing." is his philosophy.

The first evident issue was the sensitive shell, and it was substituted by his own design quite quickly. These Super Magnum shells are recommended for all Tanaka shotgun users, who want more power without having to go into the internals. The exterior is a more durable polymer material, and the base is machined high grade aluminum instead of die-cast like the originals. The ability to use all types of gas up to CO2 makes them especially versatile for various needs.

Naturally certain internal parts were improved as well, such as the firing pin, which is reinforced to withstand a stronger hammer spring and harder resistance from the high pressure shells. For the succeeding models the modifications went even further into the outer barrel.

The elevator lifts the shell into the feeding line, where it's chambered by the bolt.
The shell is actually chambered instead of having a mock bolt slide over the ejection port like in older designs.
The tube comes next. Remember: Everytime you load, you also practice the routine! Load from the carrier you actually use.


The next leap forward involved a serious reworking of the shotgun itself. Named "The Slug Shot" after the first ammo type, it is now more versatile, with two different kinds of Slugshot shells and a Buckshot shell available as well. As with a real shotgun, you can change the shells "on the fly", to choose the appropriate ammo for the situation. The barrel bore is no longer 6 mm, but over twice as big. Just like a real shotgun barrel, it isn't just any milk straw!

The Buckshot is the kind of ammo that people think of first, when they think of shotguns. The shell holds a cup and 9 BBs, all of which are shot out at the same time. Compared to previous airsoft shotgun shells, all the BBs have the same muzzle energy.

The cup and lid are lightweight and quickly caught by air resistance, while the BBs continue forward in a cluster, and spread as the distance grows. Because of this dispersion, it is safe to use for war-gaming and force-on-force training. The cup can hold pretty much anything as payload. A RAM paintball is a good alternative projectile, but in the end only your imagination sets the limits. Mixing BBs with flour or baby powder gives a nice effect when the shell is shot!

The Slugshot or just "slug" is a lump of solid material that doesn't spread when it leaves the barrel. Instead, the brute force of the projectile is applied to the same area, and it doesn't leave a small hole in the target!

The more human-friendly training slug weighs 1.9 grams, and is best suited for Top Gas. It has sufficient power to let the other player certainly notice he's been shot. When a three-gram slug is shot even a little bit harder than you can throw one, it may quickly become uncomfortable for the opponents in war-gaming. Obviously the main purpose of the heavier slug shot is practice and training use with no live targets. Compared to the 1.9 gram slug, the 3.0 gram version provides better accuracy and performance with CO2.


To charge the gas, you will need to disassemble the shell. First, pull the metal core and polymer exterior apart. It will be easier and prolong the O-ring life if you rotate it at the same time. The slug or buckshot can simply be pushed out of the polymer exterior.

To reset the gas valve, push the fill-valve down. The mock primer in the rear of the metal core will not be completely flush, but a little bit recessed. Then fill the gas as with any gas operated airsoft model. The shells are good for anything up to CO2 (500 PSI max.), and the metal core is identical between the shells.

The components from the left: Core, Exterior, Slug.
Reset the valve by pressing down.
This is the obvious part we all know: Gas it up!

The next step is to reattach the polymer exterior and metal core. Again, rotate it as you push to make it easier on yourself and the O-rings. The shells have their distinct exterior parts, and the buckshot can be recognized by a small step inside, that prevents the shot from sinking in too deep.

As you push the slug into the shell, you will notice that the air has nowhere to escape, because the system is sealed. Push the slug as far as it goes, and then pull the exterior a little bit forward to clear the second O-ring. Now when you tilt the exterior a little bit, the excess air bleeds out and you can push the exterior back on. The cup of the buckshot is easier to insert into the exterior compared to the slug, as the cup is not as tight. After inserting the cup you put the BBs in, and close it with the provided lid.

Slug goes into the shell after charging and assembling it.
Pull the exterior off a bit, squeeze and tilt to bleed out excess air.
All done! Ready to load and to release mayhem!


Every single button and lever works 100% like on the real thing, and the loading procedure and feel are the same as well. This makes the shotgun a viable option for training, whether it's for sport or work, or just for the challenge of aquiring the skills. On top of the realism, the performance is really good for anyone who wants to be a shotgunner in war-games, so it's hard to say who wouldn?t want one, unless you really dislike shotguns in general.

Using a real working shotgun with blanks or other training ammo in FOF is an accident waiting to happen, unless the shotgun is somehow modified solely for that specific ammo, and made unable to chamber and fire actual shells.

The Airsoft Surgeon shotgun series caters a whole new hobbyist group as well: A realistic airsoft model in IPSC-style shotgun competition use has the distinct advantage of being legal in most countries, and free of registering as well. In addition you can build stages for practice or a competition even indoors, where real firearms would require heavy backstops and ventilation.

Airsoft guns in general are gaining popularity and credibility as training weapons, and products like this are one more reason why these toys can and should be taken seriously. Airsoft Surgeon shotguns adds to this phenomena from a fresh new angle, that has so far been left relatively unexplored.