1970s–1980s

By Robert Bruce

In the course of decades of researching various sources including military and museum archives, Robert Bruce has acquired a treasure trove of photos of what might be considered “odd and unusual weapons.” Here is a follow-on to earlier oddities that appeared in previous issues.

 Now, with apologies for some of these rough-looking images—presented as they were found—SADJ takes a look at some interesting developments in the tragic aftermath of the Vietnam debacle as U.S. and Allied forces pivoted to other Cold War conflicts and “brushfire wars” around the globe.

When the Democrat-dominated U.S. Congress cut off funding and other military aid to America’s South Vietnamese allies, a Communist victory was assured. Saigon fell in 1975 to a combined North Vietnamese Army (NVA) and Viet Cong (VC) assault spearheaded by T-54/T-55 tanks supplied by Communist China.

Although badly shaken by what many bitterly considered a betrayal of an ally and callous disregard for the sacrifice of more than 211,000 dead and wounded Americans, the U.S. Armed Forces regrouped and refocused on the harsh realities of conventional—and likely escalating to thermonuclear—warfare with the Soviet Union; a formidable and nearly equal enemy. Joined by NATO Allies (not including the French, that’s another story) “force modernization” became a priority for rapid upgrades to ships, aircraft, tanks and all types of weaponry. Leaving the big stuff to others, we’ll concentrate here on just a few notable man-portable arms that were driven by a determination to equip fighting forces with better guns and ammo—some of which were already in the RDT&E (Research, Development, Test & Evaluation) pipeline when Saigon fell.

West German Partisan Pistol: VP70M with Buttstock and Carrying Sling

CREDIT:  HK GMBH

First produced in 1970 in the height of the Cold War, Heckler & Koch’s (HK) Volkspistole 70M (literally “people’s pistol”) was intended for civilian partisans in the wake of an almost-certain USSR/Warsaw Pact invasion of West Germany. Inspired by the multitudes of cheap and simple weapons dropped by U.S. and Allies behind German lines in WWII to arm resistance forces, it was much more capable than the single-shot OSS “Liberator” pistol and even the quick-takedown British MKII STEN submachine gun. The VP70M is a highly concealable, 9mm 18-round capacity, semiautomatic handgun that instantly converts into a 2200 RPM three-round burst-fire machine pistol with addition of its buttstock/holster. Notably, it carries the distinction of being the first production-run polymer-framed handgun.

Underwater Revolver: Gun, Underwater Defense, Mk 1 Mod 0

CREDIT: ROBERT BRUCE

Like the one seen here, locked away for posterity in the arms vault of the Naval Historical Society, the Mk 1 Mod 0 was developed late in the Vietnam War for use against enemy swimmers and continued in service with men of the Navy’s Underwater Demolition Teams and SEALs in the Cold War. It’s a seriously updated techno version of the multi-barrel “pepperbox” revolver of the 1800s. The removable barrel/chamber cluster holds six sealed Mk59 cartridges, each loaded with a wickedly long, needle-like tungsten dart.

Heavy Duty Grenade Gun: 40mm Philco-Ford CROW

CREDIT: NAVAL HISTORICAL SOCIETY ARCHIVES

Because grenade machine guns firing the M79 “Blooper’s” low-velocity 40mm grenades proved inadequate in Vietnam, logic demanded a weapon that could fire the newly developed, powerful and long-reaching 40mm M384 and M385 High Velocity ammo. But how to tame this hot round’s formidable recoil in a grenade machine gun (GMG) of manageable size and weight? In 1970, Philco-Ford’s Aeronutronic Division got a developmental award for their Counter Recoil-Operated Weapon (CROW) concept: “… the principle of converting kinematic energy of the round into potential energy. The energy stored in various springs is released during the counter recoil stroke to open the barrel, eject the spent round and feed the next round.” The resulting 35-pound GMG demonstrated effective operation at rates of fire up to 400 RPM. Nice try, but the prize went to Naval Ordnance Louisville’s MK19, which is still serving today.

SAW Contender: Rodman Laboratories XM235

CREDIT: U.S. ARMY ORDNANCE MUSEUM

This interesting mini machine gun was entered in the Army’s 1975-1976 Squad Automatic Weapon (SAW) trials. Chambered in the Army’s specified 6x45mm experimental cartridge, its novel operation system—enhancing full-auto accuracy—was patented by its government design team as the Modular Lightweight Squad Automatic Weapon System, “… having symmetrical forces applied to recoiling parts by use of two parallel gas pressure rods acting in unison. An integral sprocket feed system is actuated by the recoiling parts and avoids gross asymmetrical movements about the weapon’s center of gravity resulting from shifting ammunition weight. A dual tube receiver and dual gas system is featured in the weapon.” In the end, the Army chose FN’s Minimi in 5.56x45mm NATO, serving now as the M249 light machine gun.

Fire and Forget It: TRW’s Low-Maintenance Rifle

CREDIT: AUTHOR’S COLLECTION

It isn’t PC to assert that many if not most Third-World troops are culturally indifferent to properly maintaining their weapons, so we’ll just present this one as an interestingly cheap and simple shoulder weapon for U.S. counterinsurgency forces to arm certain soldiers. Responding to a 1971 Army requirement, the Thompson Ramo Wooldridge group (TRW) offered this 7.26-pound, 34-inch-long, 450 RPM, 5.56mm Firestick, only externally reminiscent of the superlative, sophisticated WWII German FG 42. Its equally simple and cheaply printed 1973 Tech Manual dryly notes in typewritten prose: “… a 5.56mm magazine-fed, gas operated, air cooled, shoulder weapon … designed for use as an automatic weapon and functions from the open bolt position. … The rifle is fabricated from corrosion-resistant materials and is semi-permanently lubricated by the dry film process.” Less than a dozen were made, and the project was abandoned. After all, millions of uncannily reliable AKs were available worldwide—super simple, dirt cheap and with mountains of 7.62x39mm ammo.

Piggyback Projectiles: Frankford Arsenal’s Folded Ammunition

CREDIT: U.S. ARMY ORDNANCE MUSEUM

Some engineers—ever eager to explore even marginal improvements to conventional cartridges—have produced some genuine oddities. Not the least of these is presented in a “Feasibility Study of 5.56m Folded Ammunition System,” published in September 1976 by the Munitions Development and Engineering Directorate at the Army’s Frankford Arsenal. Citing advantages including efficient stowage, higher performance in less overall space, weight reduction, etc., it boasts: “The shorter ammunition length shortens the weapon bolt stroke required to feed the ammunition and extract the case after firing. This feature enables a shortening of weapon length in the chamber/breech location.” So, what has transpired in some 4 decades since? Most notably not Frankford’s folded ammo but the HK G11’s molded brick caseless and AAI/Textron’s lipstick-tube cased-telescoped ammo.

BULLPUP MASHUP

“The EM-2, a British rifle fleetingly adopted in the UK in 1951 as ‘Rifle, No. 9,’ was the first attempt in the world to field a general-issue military shoulder weapon based on the ‘compact’ or bullpup system.” (R. Blake Stevens in the introduction to Thomas B. Dugelby’s 1980 Collector Grade book, EM-2 Concept and Design—A Rifle Ahead of its Time.)

Bullpup??!! Most simply defined as the term applies to small arms, a “bullpup” design puts the magazine and firing chamber behind the pistol grip/trigger group that’s typically located about midway along the length of the weapon. Why? For compactness, balance and quick handling.

There are advantages and disadvantages to this arrangement, kicking off all manner of controversy between proponents of traditional configurations and cocky challengers. Evidence of resistance to change is readily seen in the fact that the first promising young litter of Brit bullpups died from neglect. But that didn’t end the breed, so let’s zoom in for a closer look at some bullpups born in the ‘70s and ‘80s.

U.S. Air Force Arm Gun: Colt’s Lightweight Submachine Gun

CREDIT: U.S. ARMY ORDNANCE MUSEUM

Seen here circa 1969 in what’s likely a conceptual drawing from a presentation of the remarkable IMP-221 (Individual Multi-Purpose), this unique bullpup pistol, firing hot .221 Remington Fireball cartridges, was intended to be a compact and deadly efficient survival weapon for downed aviators. Credited to engineer Dale Davis of the USAF Armament Laboratories, it evolved from the more conventional Colt SCAMP (Small Caliber Machine Pistol) into an ergonomically unique solution to the challenges of producing an ultra-compact weapon with acceptable stopping power and practical range. Its bullpup design provided good balance, and the receiver with magazine along the arm provided some stability, swiveling to accommodate right or left handers.

Colt IMP

CREDIT: U.S. ARMY ORDNANCE MUSEUM

For a variety of reasons—not the least of which was the absurd difficulty of accurately shooting the thing—the USAF-Colt IMP initiative was ultimately rejected. But independent gun maker Gwinn Firearms apparently appreciated its novelty and saw potential for civilian or perhaps law enforcement sales, producing the Bushmaster Arm Pistol around 1972. It’s a very close version in .223/5.56 NATO, economically utilizing a lot of standard AR-15/M16 components such as Eugene Stoner’s familiar multi-lug, rotating bolt.

Brit Bullpups: Evolution of the “Rifle, No. 9”

CREDIT: WIKIMEDIA COMMONS

Seen on the far right is a well-worn trials version of the “EM-2” that soon followed the No. 9, likely chambered for an experimental 6.25x43mm “intermediate type” cartridge. To its left are later variants of the design; the first is identified as an XL60 in .280/4.85mm, and the more recent SA80 A2 (L85A2) in 5.56mm NATO. All of these bullpups are a radical break in British Army rifle tradition, with the SA80 series officially adopted as standard in 1987.

Intermediate Cartridge Showdown: .280 vs. .223

CREDIT: WIKIMEDIA COMMONS

On the left is the .280/4.85x49mm, the Brit hopeful in NATO’s weapon and ammo trials of 1978-1979, standing side-by-side with what became the NATO standard .223/5.56x45mm (right). The difficulty of “herding cats” applies here with each of several nations offering their favorite rifles and cartridges with the goal of standardizing to the extent possible for “interoperability.” What emerged was each nation kept its preferred rifle though chambered for America’s mandated 5.56mm fed from America’s M16 mags.

SA80/L85

CREDIT: BRITISH MINISTRY OF DEFENSE

2001: A steely-eyed Royal Marine Commando proudly cradles his newly upgraded L85A2 bullpup (topped with a well-used SUSAT day sight) while providing security for a nuclear-armed submarine during Operation Veritas. Cheaply and poorly made in Britain in the beginning by RSAF Enfield, the rifle was plagued with reliability problems, and only a radical rework by the German firm HK in the early 2000s and subsequent manufacture as the A2 version rescued it.

“Bugle” Blaster: The French FAMAS

CREDIT: U.S. AIR FORCE VIA WIKIMEDIA COMMONS

As a member of NATO, the French participate in defense of Europe and occasional forays overseas. So a certain amount of interoperability is evident in the distinctive FAMAS G2 (Fusil d’Assaut de la Manufacture d’Armes de Saint-Étienne) assault rifle including 5.56mm chambering and M16 standard magazines. The French’s quirky penchant for home-grown designs led to this delayed blowback-operated bullpup with the nickname “Le Clairon” (“The Bugle”), entering service in 1978. Interestingly, the bugle has blown its last notes, and France’s soldiers now carry the superlative German HK416. Sacre bleu!

Armee-Universal-Gewehr: The Austrian Steyr AUG

CREDIT: AUSTRIAN MINISTRY OF DEFENSE AND SPORT

With its rakish profile including integral optic and streamlined polymer housing, the AUG would seem perfect for arming starship troopers in most any sci-fi flick. Entering Austrian Army service in 1978, the Sturmgewehr 77 (assault rifle) is a truly modular weapon that can be immediately configured without tools from a standard version with a 20-inch barrel into a short-barrel submachine gun, carbine, heavy-barrel sniper rifle or a squad auto weapon firing from an open bolt. While firing 5.56mm NATO ammo, early versions were fed from proprietary waffled translucent polymer mags, an interoperability problem corrected in later NATO versions, also fitted with Picatinny accessory rails. The AUG proved enormously successful and was purchased in quantity by numerous countries, most notably Ireland, Australia and New Zealand.

Leap Ahead Assault Rifles: Advanced Combat Rifle Program

CREDIT: ROBERT BRUCE

Aberdeen Proving Ground, Maryland, 1989: Soldiers at a press preview showcase the “final four” candidates that will travel to Fort Benning, Georgia, for sudden-death playoffs on a super high tech instrumented, combat simulation range. From top left and clockwise: Steyr ACR firing flechettes telescoped inside polymer tubes; Colt ACR, a modified M16A2 firing “duplex” (two stacked bullets) in conventional brass cases; AAI ACR firing brass-cased flechettes; and the HK ACR firing 4.73mm caseless cartridges. While marching underneath the ACR program banner of “doubling hit probability,” in reality the Army was grasping for something better than its somewhat serviceable M16 rifles and NATO 5.56mm ammo. Formally launched in 1986, it flamed out 4 years and $300 million later because none reportedly achieved the stated goal. Since then, GIs have wondered if their M16s and M4s really are the best they deserve, a doubt lingering for 30 years that may be set aside by the winner in the Army’s Next Generation Squad Weapon trials.

Brick Firing Bullpup: HK G11

CREDIT: HK GMBH VIA WIKIMEDIA

Undoubtedly the most radical concept—not only in the ACR program but in any previous practical pairing of gun and ammo—this wunderkind is an engineering and tactical tour de force, birthed in the 1970s from the marriage of West German companies Dynamit Nobel and Heckler & Koch. Among its most striking attributes is its little, brick-like rectangular caseless cartridges made from a nearly magical propellant, compressed and formed with a skinny 4.73mm projectile nestled snugly in a tunnel. On detonation in the oscillating chamber, the bullet zips downrange and everything else disappears, needing no extraction or ejection. It fires in semiauto, auto (460 RPM) and three-round bursts at an astonishing 2,100 RPM. This last intended to maximize accuracy and multi-hit lethality because the third bullet is well on its way before any muzzle jump. The engineering wizardry required for this comes from a vertically oriented, disc-like “chamber” that feeds at 12 o’clock and rotates 45 degrees to align with the barrel at 3 o’clock to fire. Perplexed? Do a Wiki search for details on this German military marvel. A brilliant live-fire demonstration, starring the late, great Jim Schatz in the G11 gunner role is readily available on YouTube. Search “G11K2 Demonstration—Aberdeen Proving Ground, MD 1990.”

Dynamit Nobel’s Caseless Cartridge

CREDIT: WIKIMEDIA

A near miracle in chemical engineering and ultra-modern manufacture, the G11’s remarkable ammo is seen here with its components. The HITP (high ignition temperature propellant) is shaped into a tiny 1.3-inch long brick, hollowed out to hold a cup-shaped primer/booster and a 4.73x33mm projectile, held centered by a plastic cap. Resistant to moisture, crushing and cook off, it kicks out its 51-grain FMJ bullet at 930 m/s with scant recoil.

Caseless LMG

CREDIT: HK GmbH

Although unknown if this ever went beyond its conceptual drawing, the HK G11 system with Dynamit Nobel’s caseless brick ammo could almost certainly have been developed as a SAW/LMG in at least prototype form. Presumably, the vexing problem of cook off from overheating in fast, sustained firing would be solved in some manner, but would this work with a rotating disc chamber? Other caseless contemplations included a handgun-like personal defense weapon. In the end, West Germany’s plan to adopt the G11 died of monetary starvation because of many financial and other problems after the Soviet Bloc crumbled and “reunification” followed with its impoverished Eastern brethren.

NEXT TIME

In the next installment of Ordnance Oddities we’ll give a nod to the next 2 decades with such well-intentioned efforts as the U.S. Army’s Land Warrior initiative. What were they “imagineering” for 21^st century soldiers?

The MP9
The MP9 has been developed from the Steyr Tactical Machine Pistol or TMP, to which Brügger & Thomet acquired the rights in the early 2000s.  This innovative Swiss company has made a number of modifications, the most obvious being a side-folding shoulder stock, which transforms the steadiness of aim and the effective range.  They have also added a NATO accessory rail on top for optical sights, ghost ring rear sights with an adjustable foresight, a trigger safety (similar to the Glock system), a suppressor attachment on the barrel sleeve (B&T also make the suppressors), and translucent magazines for 15, 20, 25 or 30 rounds.  Options include a Picatinny rail under the barrel in lieu of the fixed handgrip, and a fixed skeleton rather than folding stock.  The standard colour of the body is black but green and coyote tan are also available, as is a blue version adapted to fire Simunition FX training ammunition (which can also work with the new Force on Force cartridge recently introduced by ATK) and a red “manipulation” gun which cannot fire live ammunition and is used for safe handling training.

The result is an exceptionally compact and lightweight submachine gun or machine pistol, largely made from polymer and weighing just 1.4 kg (3.1 lbs) empty.  Loaded 9mm magazines weigh 240 grams (8.5 oz) for 15 rounds to 440 grams (just under 1 lb) for 30 rounds.  The MP9 is 303 mm (11.9 inches) long with the stock folded and 523 mm (20.6 inches) with the stock unfolded.  Barrel length is 130 mm (5.1 inches).  Unlike most SMGs (with the notable exception of the Heckler & Koch MP5 series) the gun fires from a closed and locked bolt, utilising a rotating barrel locking system; it will still fire when the muzzle is pressed against the target.  The cyclic rate of fire is 750-800 rpm.  The single shot/automatic selector and manual safety switch is a push-button by the thumb.

PDW cartridges, from left to right: 5.7x28 FN, 4.6x30 HK, 9x19 NATO, and three loadings of the 6.5x25 CBJ; saboted ball, HET and frangible.

According to B&T, about 5-6,000 MP9s are sold every year.  The gun is widely exported and is now in service with many special forces and close protection teams.  The use of the ubiquitous 9mm cartridge is a significant selling point, along with the compact dimensions, the open holster (the gun clips into it) and the availability of the training versions.  The modest penetration of 9mm ammunition isn’t felt to be an issue as hardly any of the expected opposition use body armour (this may not, of course, remain the case indefinitely), and around 50m is regarded as an adequate range for its particular role.

The nearest competitor to the MP9 is the Heckler & Koch MP7.  The most obvious difference between them is that the MP7 is available only in HK’s unique 4.6×30 caliber, whereas the MP9 fires the 9×19 NATO, aka Parabellum or Luger, which is readily available from many manufacturers in a very wide range of loadings.  At least, that was the case until recently, when the first example of the B&T MP9 in the 6.5×25 CBJ version appeared.

The 6.5×25 CBJ
Carl Bertil Johansson is an experienced gun designer who has worked with Aimpoint and SAAB Bofors among others, but set up CBJ Tech to develop his idea for a high-performance cartridge.  The company, a family-run business, is based in southern Sweden and owns a Cold War bunker which provides very secure accommodation for workshops and range testing.

CBJ started development of the 6.5×25 cartridge in the late 1990s, at the time of the NATO competition to select a new PDW round.  This was intended to replace the 9×19 with longer-ranged ammunition able to penetrate NATO’s CRISAT target (equivalent to contemporary Russian body armour) at 150 metres.  The only cartridges officially tested were the 5.7×28 FN developed for the P90, and HK’s 4.6×30 for the MP7.  It proved impossible to reach political agreement on which to choose, so no decision was made.

Test results in ballistic gel, 340mm (13.4 inches) wide (bullet track from left to right): 9mm NATO ball (top), 6.5mm CBJ ball (middle), 6.5mm CBJ HET (bottom).

FN and HK both started with “clean sheet” ammunition and gun designs, but Carl Bertil decided on a different approach, reasoning that a cartridge that was interchangeable with the universal 9×19 round by means of a simple barrel swap would have a much wider appeal.  It would mean that existing guns could be adapted to fire the new cartridge, and also that guns in the new caliber could be easily changed to 9×19 if required; even the magazines remain the same.

This design principle meant that the new CBJ cartridge would have the same overall dimensions as the 9×19 (including the rim diameter) and would need to develop a comparable recoil impulse to ensure reliable gun functioning.  The cartridge that emerged from this study was the 6.5×25, with an extended, necked-down case and a short bullet protrusion.  Several different loadings in three ballistic groups have been developed.

To compete with the 5.7 and 4.6mm rounds in meeting the NATO PDW long-range penetration requirement, a sub-caliber loading is used.  The standard military “ball” loading is actually a 4mm caliber tungsten bullet in a plastic sabot.  The bullet weighs 2 g (31 grains), 2.5 g with its sabot.  There is a “spoon-tip” version designed to encourage more rapid bullet upset on impact, and a training variant using cheaper core material.  All of these are fired at a muzzle velocity ranging from 730 m/s (2,395 fps) from a 127mm (5 inch) barrel (the recommended minimum barrel length) to 900 m/s (2,950 fps) from a 305mm (12 inch) barrel.  The tungsten-cored loadings fired from a 12 inch barrel match the trajectory of the 5.56×45 NATO from an M4 Carbine and have much superior penetration to its standard SS109/M855 ammunition, being able to punch through 9mm armour plate.  From a 12 inch barrel, velocity at 300 metres is 578 m/s (1,900 fps) at which range it will still penetrate the CRISAT target.

The 6.5mm version of the MP9 has the barrel extended to 150mm (5.9 inches), giving a muzzle velocity of just over 800 m/s (2,620 fps).  By comparison, the 5.7×28 P90 and 4.6×30 MP7 both fire as standard 2 gram (31 grain) bullets at about 720 m/s (2,360 fps).  A brass-jacketed 6.5mm ball round weighs 7.5 grams (115 grains) compared with 6.2-6.4 grams (96-99 grains) for the 5.7 and 4.6 rounds and around 12-13 grams (185-200 grains) for 9mm.  Loaded 15 and 30 round 6.5mm MP9 magazines therefore weigh about 165 and 290 grams (5.8 and 10.2 oz) respectively.  Steel and light-alloy cases are being considered by CBJ, but the initial emphasis is on brass.

The other ballistic groups fire full-caliber 6.5 mm bullets.  One group, primarily intended for police use, fires lightweight 2.5 gram (38.6 grain) bullets at the same velocities as the sub-caliber loadings.  These consist of the HET (high energy transfer) brass bullet and a frangible (polymer/metal powder blend) version for use in training or when barrier penetration needs to be minimised.  The HET will also penetrate the CRISAT armour target at short range, but these rounds are most effective within 50 metres as the lightweight bullets rapidly lose velocity.  The third ballistic group has just one round – subsonic armour piercing – intended for use with a suppressor.  It is much heavier than the other bullets at 8 grams (123 grains) and can also penetrate the CRISAT target.

MP9 stripped down to show both barrels.

The 6.5×25 cartridge cases were previously made by reforming 9×29 Winchester Magnum brass, but CBJ Tech now has cases specially made for them.  These use slightly thicker brass, requiring some adjustment to the propellant loads.  The colour of the sabots has not yet been firmed up; originally these were black but this was changed to white to aid recovery from the indoor range’s backstop, which has an outer layer of shredded black rubber.  For production purposes, different colours may be used to indicate the loading.

SAAB Bofors was initially involved in helping to market the 6.5×25 while the NATO competition was running, but is no longer involved with the project.  CBJ Tech is continuing to develop the ammunition and demonstrate its capability in a wide variety of converted submachine guns and pistols.  Those tested to date range from the Steyr AUG SMG to SIG Sauer and Glock pistols.  Where necessary, pistols are fitted with barrels extended to 5 inches.  A substantial purpose-designed SMG, the CBJ MS, was initially developed to use the new round and features a folding bipod and an optional large-capacity drum magazine in order to act as a light support weapon out to 400m.  However, CBJ Tech is now mainly focused on adapting existing 9mm weapons, particularly the MP9 as this is seen as the ideal combination for the PDW role in which there is growing military interest.  The remarkable performance of the 6.5mm cartridge, especially in armour penetration, is such that CBJ is intending to offer their conversions only to military and police customers.

How it Works Together: the MP9 in 6.5×25 CBJ
Once in Sweden, I had the opportunity to test-fire the MP9 in both 9mm and 6.5mm calibers alongside other weapons for comparison purposes, in two locations; an outdoor range in semiautomatic fire and in CBJ’s indoor range on automatic.  Before this, I had only been able to handle the MP9 so I was keen to see how it performed.

In either caliber the MP9 is a pleasure to shoot.  I found the spacing between the butt, the pistol grip and the forward handgrip suited me well.  The fat, forward-sloping front handgrip greatly aids control and I would certainly not wish to do without it.  For semiautomatic fire, the little 1.5x Trijicon sight proved ideal and the effective range of the 6.5mm version firing the saboted tungsten ammunition would probably be around 200 metres.  In 9mm calibre, or for close-range work, a 1x holographic red-dot sight (also tried) might be preferred.

The author firing the MP9.

Given the MP9’s small size and weight I was surprised by its controllability in automatic fire.  As a UK civilian, my opportunities for firing automatic weapons are more or less zero but I found no trouble in keeping the rounds on target when firing short bursts; the little gun was much easier to control than an M16 I tried afterwards.

There was very little difference between firing the 9×19 and 6.5×25 versions of the MP9.  Subjectively, the 6.5mm version felt as if it had slightly less recoil.  My arrival coincided with CBJ’s working up of loads using their new cartridge cases.  They hadn’t finalised this process and the 6.5mm version suffered some failures to feed with the new cases (although it performed very well with the older ones) but that was expected to be a temporary glitch.

A key question in my mind was this: OK, the little 4mm tungsten bullet goes through armour like the proverbial hot knife through butter, but how does it perform against unarmoured personnel?  This question could only finally be decided in combat, of course, but ballistic gel provides a repeatable substitute for testing purposes.  CBJ Tech have the facilities for this, and performed some tests for my benefit.  I witnessed three different cartridges being compared at about 5 metres range; the standard 6.5mm saboted ball (this one first had to penetrate a CRISAT target), the full-caliber 6.5mm HET and the 9×19 NATO FMJ.  The least impressive was the 9mm, while the 6.5mm HET showed far more disruption with rapid bullet upset.  The saboted ball also performed significantly better than the 9mm, and according to previous tests I was shown, the spoon-tip version demonstrates even faster upset as one would expect.  Interestingly, on one of the test shots of the saboted rounds the sabot was found stuck into the surface of the gel block, which showed that it had followed the bullet down-range quite closely.

9mm thick armour plate from a Russian vehicle, showing penetration by 6.5mm CBJ ball.

In summary, the Brügger & Thomet MP9 is arguably the best of the new breed of PDWs – or machine pistols or compact SMGs if you prefer.  For only about double the size and weight of a pistol (but half the size and weight of an M4 Carbine) it offers perhaps ten times the effective range plus controllable automatic fire.  The use of universally-available 9×19 ammunition is proving to be an important benefit, but if more range or penetration is required the gun can easily and reversibly be converted to the impressive and versatile 6.5×25 CBJ.  For any military or law enforcement organisations contemplating a weapon in this class, this could be a winning combination.

More information about the 6.5×25 ammunition is presented on the CBJ Tech website at: www.cbjtech.com.  Brügger & Thomet’s website is: www.brugger-thomet.ch/.

Anthony G Williams is an independent ammunition consultant and co-editor of Jane’s Ammunition Handbook.  He maintains a website at www.quarry.nildram.co.uk.