During the Vietnam War, one of the most notable small arms in history was developed and fielded in limited numbers, primarily among Navy SEAL teams. It was officially designated the Mark 23, but was best known simply as the Stoner 63. The Stoner 63 was probably Eugene Stoner’s finest achievement, designed from the outset as a true modular firearm that could be configured in several different ways using a single receiver.
The original could be set up as a rifle, carbine, Bren-type top-feed light machine gun or as a belt-fed light machine gun. The Stoner 63 used a rotating bolt similar to that of the M16 but did away with the M16’s Ljungman-type direct impingement gas system in favor of a piston connected to the bolt carrier, similar to AK rifles. In its belt-fed light machine gun configuration, the Stoner 63 fired from the open bolt.
The Stoner 63, however, used magazines that did not interchange with the M16. Fewer than 5,000 Stoner 63s were manufactured in all of its various configurations, and the U.S. government has destroyed about 2,700 of them during the past few years. Today, there are fewer than 200 original Stoner 63s in private hands in the United States, making it one of the rarest military small arms in history.
At first glance, the Robinson M96 looks like a Stoner 63. It should, as the Robinson Arms
engineers used the Stoner 63 as a starting point in designing the M96, although the only Stoner 63 component that will fit an M96 is the stock. The M96, like the Stoner 63, is modular but does not incorporate the belt-feed feature of the original. Although, if the need ever arises for a belt-fed version, it would be a straightforward modification.
As it is, the M96 is essentially an improved Stoner 63, modified so that it fires semiautomatic only from the closed bolt. The M96 has been improved over its predecessor in several ways. The recoil spring was moved outside the operating rod, and the operating rod and bolt carrier were separated into two components. Unlike the original Stoner 63, the M96 bolt carrier can be removed with the operating rod in place. The bolt carrier also has been modified from that of the Stoner 63.
While the M96 bolt carrier cam pin arrangement is virtually the same, the carrier cap has been simplified, and the rails on which the carrier rides in the receiver have been modified from two full-length rails to four mini-rails positioned at each corner. This enhances reliability and reduces friction.
The M96’s six locking lugs are significantly larger than the seven of the Stoner 63 and have been modified to more evenly distribute recoil forces and strengthen the rifle’s lockup. The two locking lugs adjacent to the extractor are significantly larger than the remainder to prevent cracking. The seventh lug adjacent to the ejector slot has been eliminated entirely.
The M96 extractor is standard AR, but the AR’s Garand-type spring-loaded ejector is absent. In its place is a simple spring-loaded post in the magazine well that forcibly ejects spent casings. The firing pin is spring-loaded to prevent slam fires. The M96, of course, uses standard AR-type magazines.
The M96 operating system is unique and contributes to the rifle’s reliability while facilitating cleaning and maintenance. The operating rod and bolt carrier are separate but locked together when the rifle is in operating condition. The recoil spring surrounds the operating rod like a SIG550 or Beretta AR70, but the M96 is different from both.
A key feature of this system besides its reliability is that it eliminates the AR-15 direct impingement gas system. Because it has a long operating rod and excess gas is bled off at the muzzle end of the rifle, the receiver remains virtually free of carbon fouling, unlike AR-type rifles that require intensive maintenance because of carbon fouling buildup. Moreover, when the M96 does require cleaning, it is a far simpler and a less time-consuming chore than with ARs. In addition to simplicity, the M96 gas system can be adjusted if necessary.
Like the Stoner 63, the Robinson M96 has a quick-change barrel feature, but it is again slightly different. To remove the barrel for cleaning or to change to a different barrel, all that is necessary is to retract the bolt, lock it to the rear, and depress the square button on the bottom of the forearm just forward of the magazine well. When the button is depressed, the barrel can be withdrawn. Replacing the barrel is simply the reverse.
Changing from a 16-inch to a 20-inch barrel or vice versa is almost as simple. The 16-inch and 20-inch barrels use different length gas cylinders and operating rods, so it is necessary to change these when changing to different length barrels. To change barrel length, press in on the operating rod release on the bolt carrier at the forward end the ejection port. Move the bolt carrier slightly to the rear to free it from the operating rod. Withdraw the barrel.
Looking at the rifle from the front, press the operating rod slightly to the rear to disengage the locking lug and rotate the rod 90 degrees counterclockwise, being careful to control the rod because it is under spring pressure. Let the rod move forward under spring pressure and withdraw it. Using the nose of a bullet or similar tool inserted into the gas vent holes at the front of the gas cylinder, work the cylinder back and forth while pulling out on it and withdraw it. The gas cylinder is a press fit in the receiver and requires little effort to remove.
When reassembling the gas cylinder, it should be noted that the forward end has a small and a large hole on opposite sides. Align the gas tube with the receiver and again, using the nose of a bullet or similar tool as a lever, rotate it back and forth while pressing downward. Make sure that the gas cylinder is fully seated and that the smaller of the two holes at the forward end of the tube is pointed up and away from the barrel. The barrel will not lock into place unless the cylinder is fully seated.
Insert the operating rod into the gas cylinder with the locking lug up. Press in until about a half-inch of the operating rod protrudes beyond the end of the gas tube. Rotate the operating rod 90 degrees clockwise and ease it forward to ensure that it is locked in place. The bolt carrier locking notch should be facing away from the ejection port. Hold the barrel release and insert the barrel. Press the bolt carrier forward until it locks to the operating rod.
It actually takes less time to accomplish this than might be imagined. After learning the procedure, we can change over from a full-length rifle to carbine and vice versa in less than 2 minutes. Besides the ability to go from one barrel length to another, the M96’s quick-change barrel facilitates cleaning.
The barrel and operating rod are simply withdrawn and cleaned as separate units, a vast improvement over AR-type rifles that require special brushes, pipe cleaners, scrapers and other paraphernalia to effectively clean the rifle. Once the barrel and bolt carrier have been removed, access to the receiver is very easy and cleaning is a snap. No special equipment is necessary. The M96 is the easiest semiautomatic rifle to clean that the author has ever encountered.
Moreover, the ability to withdraw the barrel means that the M96 can easily be changed from one caliber to another. By merely changing barrel and bolt head, the rifle can be converted to the recently introduced 6.8x43mm SPC cartridge. A conversion unit for this caliber is under development.
The stainless steel receiver of the M96 is equally innovative. The magazine well is a separate unit that can be removed and replaced. The charging handle is on the left side of the receiver, a real convenience for right-handed shooters who do not need to remove the rifle from their shoulder or their strong hand from the gun to engage the charging handle. The magazine release is one of the best we have encountered.
Once a fresh magazine has been inserted into the mag well, all that is necessary to release the bolt is to move the trigger finger down where it naturally meets the bolt release. The magazine release is just above the bolt release in about the same position as a standard AR.
The M96’s satin black finish is a Robinson Armament proprietary process that eliminates rust and has an extremely high surface hardness. It seems impervious to scratching or marring. The fit and finish of the stamped parts is excellent, and the weld quality is outstanding.
Our rifle also came with the optional MIL-STD-1913 optic mounting rail on the upper receiver. Although this feature is optional, it is an item that we believe should be standard, as most users prefer to add an optic, as it enhances target engagement speed, and when a police officer needs a long gun, speed equals survival. This brings us to our sole complaint about the M96.
Although the optional rail was a foot in length and included an AR-type aperture rear sight adjustable for windage, the rail would not accommodate a Holographic Weapon Sight (HWS) unless two of the eight mounting screws were removed. This is because the screw heads are not flush and prevent the HWS from achieving its interface with the rail surface. Once we removed the two screws, the HWS clamped right into place.
The second part of this minor complaint is the rail itself. While it is generally to MIL-SPEC-1913, the surface above the screw attaching points lacks a channel. The channels are what optics lock into to limit fore and aft movement. The absence of two channels is really not a major shortcoming, but serious operators who use carbines with MIL-STD-1913 rails insist on an uninterrupted surface. Why?
Because just as we did, they find that Murphy’s Law is always in effect, and if there are places on the rail that have no channel or where screw heads protrude, those places are exactly where you will need to mount the accessory you are trying to install. We also got the handguard with MIL-STD-1913 rails on the bottom and sides. We would like the side rails a bit longer—at least twice as long as they are. The bottom rail also should be extended.
Most readers are familiar with the EoTech Holographic Weapon Sight, so we will not go into great detail regarding it. The HWS projects a laser hologram onto a piece of hardened glass and emits no telltale light to the front to attract unwanted attention. The sight has a 1 MOA dot surrounded by a 65 MOA circle. This draws the eye instinctively to the target and is much faster than simple red dot sights.
Moreover, if the batteries fail, the sight is still usable at CQB distances of 50 yards or less. In fact, some special operations users do not even turn on the reticle, but simply frame their targets in the window and shoot. The HWS reticle will function as long as there is part of the glass intact.
Military personnel have been buying HWS’ out of their own pockets for some years, but the Army is now buying them by the thousands. The military specification HWS has a full 10 levels of night vision compatibility in addition to being waterproof to two atmospheres.
Laser Devices’ MOLAD (Multi-Operational Laser Aiming Device) is less well-known than the HWS but is a very useful and versatile device that incorporates visible and infrared (IR) lasers along with a 95 lumen white light in a very compact package that mounts to any MIL-STD-1913 rail interface.
Both laser aimers are fully adjustable for windage and elevation, and the MOLAD can be actuated from body mounted switches or from a pressure pad. Instead of taping the pad to the handguard, we made use of a new Tango Down vertical foregrip available from Buffer Technologies. The vertical foregrip has a removable panel that covers a slot that perfectly accommodates a pressure pad like the one for the MOLAD. The bottom screws off to reveal a compartment for spare batteries.
Shooting the M96 was a revelation. We are used to shooting AR-type rifles, and while some are better than others, they all feel pretty much alike. The M96, however, has a different “feel” that is hard to describe. It is the smoothest functioning .223 semiautomatic rifle we have ever fired, which, of course, makes it also the most controllable in rapid fire.
We allowed several police officer friends to shoot the M96, and everyone agreed that the M96 was the best .223 they had ever experienced. One SWAT officer left the range, went to a local gun store and immediately ordered an M96 of his own. The rifle is THAT good! The trigger is a two-stage type. Once the first stage slack is taken up, there is a small amount of creep before the trigger breaks.
Our test rifle’s trigger broke at 6.5 pounds, but it felt lighter. As mentioned, we installed a HWS on the rifle and carbine but used the aperture sights on the “Bren Gun” top-feed version for our informal shooting.
Our formal testing was limited to the standard rifle, although we informally fired the carbine and “Bren Gun” configurations. The M96 functioned reliably in all configurations. We initially had a few stoppages with the carbine barrel using match ammo when the open-tipped nose of the bullet deformed and stopped against the feed ramp, shoving the bullet back into the cartridge case.
Full metal jacket cartridges functioned without a hitch. The match ammo problem was eliminated by lightly polishing the feed ramp. We tested the carbine barrel of the aforementioned police officer’s M96 carbine with match ammo, and functioning was flawless.
The M96 is without doubt the smoothest functioning .223 caliber rifle or carbine we have ever experienced. With its quick-change barrel and outstanding ergonomics, such as left-side charging handle and ambidextrous bolt release, it improves on the AR-15 in several ways. Cleaning is also simplified because of the operating rod gas system and removable barrel and magazine well.
The smooth operation has to be experienced to be appreciated. Another advantage of the M96 is that it has a unique “look” that distinguishes it from AR-15-type rifles or carbines. Because some departments disapprove of the “military” connotation afforded when officers carry AR-15-type long guns, the M96 is more “PC” than an AR of any type, while being an improved design in every way.
We liked the M96 so much that we had to have it for duty use. The M96 has now replaced our AR-type carbine on patrol. We recommend the M96 without hesitation to either police officers for duty use or to civilians seeking an excellent carbine for sport or defense. Charlie Cutshaw is a small arms, ammunition and infantry weapons editor for Jane’s Defense Information. He served as an Army infantry, an ammunition officer and an intelligence officer before retiring in 1996. His military assignments included a tour of duty in Vietnam as an adviser. He currently lives in Alabama, where he is a full-time writer and reserve officer. He can be reached at CQCutshaw@aol.com.