SDM M77 Commando: the Chinese bull-pup
The Sino Defense Manufacturing (SDM) M77 Commando is a quite simple, almost spartan, and yet interesting semi-automatic bull-pup sporting rifle manufactured in China
Manufactured in China by the SDM company, the M77 Commando rifle is a lightweight and handy bull-pup rifle distributed by Prima Armi of Italy
In 1997, a new modern and simple bull-pup service rifle was observed in the hands of the People's Liberation Army soldiers: it was the QBZ-95, entirely developed in China and chambered for the proprietary 5.8x42mm light cartridge.
An export version of that rifle was also developed – dubbed the QBZ-97 – which replaced the proprietary caliber with a standard 5.56x45mm NATO chambering and fed through standard M16-type magazines; it was sold to the militaries of Bangladesh, Cambodia, Myanmar, Pakistan, Sri Lanka and Sudan (and probably to other non-disclosed recipients), and as the years went by, both the QBZ-95 and the QBZ-97 lines were expanded in many variants.
The M77 Commando is a civilian-grade variant of the Chinese-made QBZ-97 Carbine
Towards the end of the 2000s, semi-automatic variants started to surface – aimed specifically to the western civilian markets.
The first batches of those modern sporting rifles were distributed in Canada, starting in 2008; around six years later, they were imported in Europe.
Today the only civilian-grade version of this bull-pup rifles line available to European shooters is the S.D.M. M77 Commando semi-automatic rifle.
The M77 Commando is noticeably lightweight and handy, even for a bull-pup
Bull-Pup, made simple
The S.D.M. M77 Commando is a civilian-grade variant of the QBZ-97B – also known as the NQZ03B (97) according to some sources – which would be the short carbine version of the baseline QBZ-97 rifle: a firearm conceived for Police, special forces, close protection, vessel protection, and other similar purposes.
Right side of the SDM M77 Commando 5.56mm bull-pup semi-automatic rifle
Left side of the SDM M77 Commando 5.56mm bull-pup semi-automatic rifle
The M77 Commando comes with an integrated foregrip that dubs as a handguard
The STANAG 4179 compliant magazine well will accept most AR-15 compatible magazines
A close-up of the SDM M77 Commando's peculiar flash hider
Many differences among the S.D.M. M77 Commando semi-automatic rifle and its full-automatic counterparts do immediately meet the eye.
The M77 Commando sports a remarkably longer barrel than the original assault carbine – 365mm (14.37"), which brings the overall length to 62 centimetres (24.4 inches).
That's due to the fact that in most European Countries, as per the provisions of the European firearms directive in its current form, firearms will qualify as long guns only if they are longer than 60 centimetres overall and sport a barrel that's longer than 30 centimetres.
For the rest, the S.D.M. M77 Commando rifle is just like the original automatic carbine: the receiver is manufactured out of steel, and the barrel is secured to it along with the gas system.
The cheekpiece and the two upper and lower halves of the chassis that wraps around the barrel and the gas system – with the upper part hosting the carrying handle and the other including the trigger and the relevant, extremely simple transfer bar – are manufactured out of high strength polymer.
The reciprocating cocking handle of the M77 Commando is located under the carrying handle
The cocking handle of the M77 Commando rifle also dubs as the hold open release catch
Despite the relatively odd position, the cocking handle is fairly easy to reach and operate
The reciprocating cocking handle of the S.D.M. M77 Commando is connected to the gas piston, and dubs as a hold-open release device; as such, it is protected by the raised carrying handle, which also hosts the adjustable peep-type rear sight.
A two-position safety switch is located on the left side of the stock, behind the magazine well, while the magazine release button is located on the right side of the magwell itself.
The front sight assembly also hosts the gas valve adjustment system
The only other control to be found on the M77 Commando rifle (exception made for the trigger, of course) is a manually-adjustable two-positions gas system valve, located at the base of the front sight ramp.
The Sino-Defense Manufacturing M77 Commando semi-automatic rifle is a long-stroke piston driven system and sports a proprietary bolt design which includes a three-lugs bolt head and a striker-fired setup. This is one of the very few examples of non-hammer-fired modern military or sporting rifles.
The M77 Commando rifle can be stripped by removing a wide metal pin located just in front of the rubberized shoulder recoil pad; this will release the cheekpiece and allow the removal of the entire bolt assembly, gas piston, and return spring.
Once that's done, another pin can be removed from the lower half of the chassis, just behind the pistol grip, and both the upper and lower polymer portions will be released. The field-strip is extremely simple to carry on, and the gun has very few parts to account for – and basically none that would be small enough to get lost in the process.
Shooting the M77 Commando
The SDM M77 Commando rifle in a firing position
The S.D.M. M77 Commando has a lot more going for it than it meets the eye at a first glance. First of all, the shooting impressions will be extremely pleasurable for a bull-pup: the trigger is long but light, and doesn't creep.
The already low .223 Remington/5.56mm NATO caliber recoil is kept to even lower levels thanks to the proprietary conic flash hider whose cylindrical bases screws on to the muzzle.
Dubbed XTR-33, the flash hider is part of the gas system itself and is secured in place by a spring-retained metal tube secured to one side of the barrel.
The rifle makes large use of polymer.
We have tested the SDM M77 Commando in a very rough and instinctive way, exactly to collect realistic impressions on its field use.
Photo: two groups made with the rifle's open sights.
Left, 5 shots group at 15 meters, rapid fire
Right, 3 shots group at 25 meters, slow fire
The ejection window is located on the right side of the receiver
Plus: while the ejection window is located only on the right side of the receiver, the M77 Commando tends to eject the cases very violently, upwards and forward. A complication for reloading enthusiasts who may want to pick up their spent cases after use, but a relief for those who may want to fire their rifle from the left shoulder without being getting a hot brass kiss.
The weight of the M77 Commando is extremely well balanced, which is once again something uncommon in bull-pups, and the accuracy is higher than one would expect from a Chinese firearm, given the six-grooved, 1:7" pitch barrel.
Once again: the test was merely addressed to test its potential as a range gun rathern than to establish how tight a pattern it could produce, but results indicate that it would perform more than reasonably in dynamic shooting competitions and defensive use.
The M77 Commando rifle is a well-balanced, if odd, design
Just like any other firearm, the S.D.M. M77 Commando has its downsides. The first imported batches tend to suffer from severe constant misfeeds and jams, and to perform unreliably with many types of magazines. Told this, the gun run flawlessly.
One of the drawbacks of the M77 Commando rifle: it's choosy when it comes to magazines
Metal AR-15 type magazines and thinner polymer magazines like the MagPul P-MAGs are the best choices for the M77 Commando; other polymer magazines such as the CAA, MWG and others may have a hard time fitting and removing due to the very tight, strictly military-spec dimensions of the magazine well. The issue can be solved by using somewhat "worn" magazines or by peeling off some material from the rear portion of the mags themselves before use.
Sights can be seen as another issue. The sighting line axis is very low, since the original project was dimensioned for the anatomy of the average Chinese soldier, who's noticeably smaller than the average Westerner.
The rear sight can be manually adjusted, but the front sight requires an AK/AKM sight adjustment tool.
The sighting plan of the M77 Commando is just a little bit too low for the average build of a western shooter
If anything, the SDM M77 Commando is quite comfortable to fire from the hip
The M77 Commando comes with a proprietary sight bracket that will require an aftermarket Picatinny rail to mount sights
An optics mount (actually protruding from the receiver itself) is located on top of the carrying handle, but it's a proprietary mount conceived for Chinese military optics. The issue was first solved for the Canadian commercial market by small local companies that manufactured drop-in Picatinny interfaces that would use the proprietary mount as a base.
As plain and spartan as it gets, the M77 Commando has none of the typical tactical accessories interfaces so common in modern military firearms. Shooters can circumvent this issue by using general-purpose aftermarket interfaces as offered by countless Companies on the market.
Given the additional width provided by the flash hider retaining rod that runs on the right side of the barrel, said interfaces can be installed around the barrel itself without wobble, and they will not come loose or fall down during fire – even sustained fire. The user would however exercise caution when tightening down the interface to prevent damage to the flash hider retaining rod.
The double grip design is one of the most unique features of this rifle
The safety switch is located on the left side of the stock, behind the magazine well
The S.D.M. M77 Commando semi-automatic rifle is tough and rustic... and utterly reliable, particularly since the issues with the first lots were solved.
With more than satisfactory accuracy, simplicity in field-stripping and a STANAG-compliant magazine well that delivers the shooter from the use of hard-to-find magazines, the M77 Commando is the cheapest bull-pup rifle on the European civilian market.
S.D.M. M77 Commando - Technical specs
S.D.M. - Sino Defense Manufacturing
M77 Commando
Semi-automatic rifle
5.56x45mm / .223 Remington
Adjustable long-stroke gas piston system, rotating bolt
Striker fired single-stage, single action
Manual two-positions safety switch
STANAG 4179 (AR-15 compatible) detachable magazines of any capacity
365 mm / 14.37 inches
Six right-handed grooves, 1:7" rifling pitch, XTR-33 conic flash hider with screw-on cylindrical base
Rear sight adjustable for range; AKM-type front sight adjustable for windage and elevation
Proprietary base for optics or additional Picatinny interfaces
610 mm / 24.4 inches
2,9 kilograms / 6.39 oz.
Steel receiver and barrel, polymer cheekpiece, polymer upper and lower chassis halves
€ 1,399.00