The sinking of the South Korean Corvett - many technological questions unanswered

Although I have not been following the sinking of the South Korean warship closely, I am quite intrigue with the "how" it could happened. Without the benefit of reading the full report of the incident, my opinions are based purely on the newspaper articles as well as internet news portal on the event.

The incident:
"In the dead of the night, a large explosion suddenly erupted which cased power in the ship to cut-off. Immediately, the ship started to split into two and started sinking."

Allegation:
"Based on forensic evidence, it was alleged that the ship was hit by a torpedo fired from a submarine at close range."

Here is where I do not get it. How could a warship with first world technology unable to detect a submarine that is so closed (the alleged submarine was of an old soviet design with cold war era technology)? How could the same ship cannot even detect a speeding torpedo launched against it?

The South Koreans and the American must answer these two questions fast. Otherwise the whole "invincibility" persona of modern Western technology is suspect.

DENEL PAW-20 "Neopup" handheld grenade launcher (South-Africa)

PAW-20 with night vision sight and laser pointer. Note that magazine projects well below its housing

PAW-20 grenade launcher, right side. Note that it has dual Picatinny rails which host collimating (red dot) sight at left, and a laser pointer at right

Representative of DENEL Corp demonstrates PAW-20 weapon

20mm ammunition for PAW-20 grenade launcher (shown are High Explosive Incendiary rounds)

Caliber: 20x42
Type: semiautomatic, magazine fed
Overall length: 845 mm
Weight: 5.9 kg unloaded
Effective range: up to 1000 m (area targets)
Magazine capacity: 7 rounds

PAW-20 (PAW stands for Personal Assault Weapon) is a most recent development of the South-African company Gemaco Elbree Pty Ltd, and is marketed by South African military corporation DENEL. Ammunition of new type, developed for PAW-20, is produced by the PMP - DENEL munitions. While in some advertising texts the PAW-20 was listed as a "new assault rifle", it is obviously not a true assault rifle, but, rather a semi-automatic grenade launcher, which is intended as an infantry support weapon. PAW-20 fires specially developed explosive ammunition of 20mm caliber, using relatively short, straight cartridge cases. Muzzle velocity is about 300 m/s, which is quite low by artillery standards but rather high by standards of hand-held grenade launchers. Intended targets for PAW-20 are infantry in the open and behind light covers, as well as unarmored or lightly armored vehicles and thin-walled buildings. While maximum effective range for PAW-20 is given as 1000 meters, it is obviously stated for "area" targets such as groups of soldiers; against point targets like cars or machine gun nests, effective range will be much less probably no more than 300-400 meters - unless gun will be used in conjunction with laser rangefinder and computerized sight with built-in ballistic calculator.
 
Standard ammunition at this time is available in HE, HE-I and TP (practice) variety, with other types being in development. Weight of the round warhead is listed as 105 gram, and it seems that new round consists of a standard 20mm projectile (as used in aircraft cannons) loaded into short, straight-walled case of 42mm length. All ammunition is point-detonating only, unlike the American XM-25, to which PAW-20 is a direct competitor.

PAW-20 is semiautomatic, gas operated weapon with rotary bolt locking. The entire barrel / bolt group is allowed to recoil within the polymer gun housing for about 75mm (3"), in attempt to decrease peak recoil down to manageable level. General layout of the gun is somewhat unusual as the pistol grip with the trigger is located at the right side of the receiver. Gun is fed from detachable box magazines which hold 7 rounds of ammunition. Empty cartridge cases are ejected through the window on the left side of the weapon, right in the front of the firer's face. Sighting equipment is installed on two Picatinny-type rails located in parallel at the top of the gun housing. Preferred sighting arrangement seems to be a red-dot type collimating sight, but other sight options also available.

Smith & Wesson Model 500 .50-Cal. Magnum Is The King Of Handguns

Smith & Wesson crowns the new king of handguns with its Model 500 S&W Magnum revolver

In the 1971 movie "Dirty Harry," actor Clint Eastwood introduced the world to the double-action Smith & Wesson Model 29 .44-cal. Magnum revolver—"the most powerful handgun in the world."

It was a crown S&W wore proudly, albeit briefly.

The rising popularity of handgun hunting for big game (spurred largely by the .44 Magnum itself) prompted the introduction of newer and significantly more powerful revolver cartridges. Many powerful enough that they had to be chambered in single-action handguns because existing double-action designs could not contain the recoil forces and pressures they produced.

Since S&W does not make single-action revolvers, and no double-action frame at its disposal could handle the new loads, S&W was effectively dethroned.

At the 2003 Shooting, Hunting and Outdoor Trade (SHOT) Show, the manufacturer regained its crown. And, most significantly, it did it by introducing a new massive double-action revolver that is chambered for an equally new .50-cal. cartridge.

The S&W X-frame Model 500 is a brawny handgun designed to master the most rigorous hunting fields in the world. It is not a revolver one would, or likely could, tuck into a waistband. In fact, to call it massive is an understatement.

With its 8-3/8-in. barrel, the overall length of the Model 500 is 15 in. and the empty weight is 4.5 pounds. The cylinder alone is almost 2 in. in diameter and approaches 2.25 in. in length. Thumb the cylinder open and five charge holes await. Each is 1/2 in. in diameter, and the .50-cal. cartridges they hold are almost 2 in. long. Load five of them and the total weight of the handgun climbs to 5 pounds.

You don't just casually pick up a Model 500. You have to lift it.

Fire even one of those big cartridges and you'll appreciate why the weight and mass are there.

When the .44 Magnum laid claim to being the most powerful handgun in the world, its standard load produced about 900 ft.-lb. of muzzle energy. Several new loads have since eclipsed that, but the handgun most commonly used by big game hunters is the .454 Casull, which will generate about 1900 ft.-lb.

The 500 S&W Magnum will produce almost 2600 ft.-lb. with its heaviest load, and more powerful loads may well be on the way.

If Dirty Harry felt that the .44 Magnum would make his day, the new 500 S&W Magnum would certainly make his decade. It is the largest double-action revolver available, and there is no production revolver in the world—single or double action—capable of matching, or even approaching, the level of power it produces.

Harnessing that power in a double-action revolver, however, required some departures from traditional designs.

Rethinking Double-Action Design
No frame in the S&W line was capable of containing the 500 Magnum, so the new X-frame was designed specifically for the 500's .50-cal. cartridge. It is massive. But, just making a bigger double-action revolver was not the solution. A major concern was the barrel-to-frame connection. This is traditionally done by simply screwing the barrel into the front of the frame, but this design places all firing stress at that one point. To increase strength throughout the 500's barrel assembly, S&W opted for a composite barrel/shroud system.

A stainless steel barrel tube is torqued into the frame to form a solid rear attachment point. A separate, heavy stainless steel shroud is then slipped over the barrel and braced against the forward portion of the frame. The muzzle end of the barrel bears against the forward end of the shroud, and a separate compensator/muzzle brake is then rotated into place under torque at the muzzle end of the shroud.

This arrangement compresses the shroud and places the barrel tube under tension for its entire length. In effect, the barrel and shroud act as linear springs to distribute the stress of firing across the entire barrel/shroud component instead of focusing it all at the single junction of the barrel and frame.

Maintaining precise cylinder alignment was another concern. Traditional designs utilize a front- and rear-cylinder lockup, with the forward end of the ejector rod bearing against a ball-detent fixture on the barrel to provide the front lockup. Given the power of the 500 Magnum, the potential for flex in the ejector rod had to be addressed. The solution was to dispense with that design and install a massive ball-detent lock on the frame itself, directly below the barrel forcing cone. This mates with the yoke to provide a solid front lockup directly at the front of the cylinder. Combined with the traditional rear lockup, this is the strongest cylinder alignment design possible.

While the 500 S&W Magnum answers the question of "where's the beef?" the company wisely decided to incorporate the same grip dimensions found on its much smaller K-frame handguns. Experienced handgunners regard this as one of the best handgun grips ever made.

Thus, the 500 Magnum is a big revolver that's strong where it needs to be, but is comfortable to handle. That was borne out during firing tests.

SPECIFICATIONS: 500 S&W Magnum

Caliber: .500 S&W Magnum
Barrel: 8-3/8 in.
Capacity: 5 rounds
Front Sight: Interchangeable black blade
Rear Sight: Micrometer click-adjustable black blade
Grips: Hogue rubber, energy absorbing
Weight (empty) : 72.5 ounces
Material: Stainless steel
Finish: Satin stainless
Overall length: 15 in.
Other features: Internal key lock and recoil muzzle compensator


On The Firing Line
Despite the power of the cartridge, the 500 S&W Magnum is surprisingly controllable. Due largely to the sheer mass of the revolver (combined with the muzzle-heavy balance and an excellent muzzle brake), the violent wrist-wrenching muzzle whip associated with single-action revolvers firing such powerful loads as the .454 Casull and the .475 Linebaugh has been tamed considerably.

In those guns, muzzle rise on recoil can reach 90° and present a hazard to the shooter. With even the heaviest 500 Magnum load tested, muzzle rise was confined to the 50° range and there was never any concern about the shooter wearing an imprint of the front sight in his forehead. That does not mean it's a pussycat. Make no mistake about it, this is not a handgun for the timid or the inexperienced. In comparison tests, the lightest 500 load—the 275-grain jacketed hollowpoint at 1665-ft.-per-second (fps) velocity—produced a modest, but noticeable, increase in recoil levels over a S&W Model 629 .44 Magnum. Anyone who is uncomfortable with the .44 Magnum will be decidedly uncomfortable with the 500 Magnum. The 440 cast-lead load at 1625 fps raised the recoil bar significantly. Muzzle rise still remained under 50° and placed little or no stress on the wrists, but the rearward thrust absorbed by the shooting hand began to become uncomfortable after 10 to 15 rounds. A shooting glove would have mitigated some of that.

Still, considering that the projectile weight and velocity of this load is virtually identical to a 1-ounce 12-ga. rifled lead shotgun slug—and that the 500 Magnum operates at over four times the pressure level of the slug—the recoil was less than expected. We'd say that Dirty Harry would certainly approve.
One of the more unusual aspects of the Model 500's creation is that S&W developed the cartridge first. Only when the gunsmiths had the performance levels they wanted, did they design and build the revolver that would fire it.

The cartridge design was handled by Cor Bon of Sturgis, S.D., which has extensive experience in that field. The guidelines the company received were firm: The bullet had to be precisely .50-cal., and the operating pressure could not exceed 50,000 psi. It had to produce at least 2200 ft.-lb. of energy with its heavier loads, and the overall cartridge length could not exceed a certain figure.

According to Cor Bon, the task was easier than it sounds.

Research determined that no existing cartridge case would meet the specifications, so a completely new, straight-walled .50-cal. case, measuring 1.625 in. in length (using standard large-pistol Magnum primers) was designed and produced. A pressure barrel was built, and the testing of powder and bullet combinations began.

It quickly became apparent that the energy requirements could easily be met, and at significantly lower pressures than the maximum allowed. The search then turned to those specific bullets that would provide the best terminal performance. That was done through actual hunting field tests and took almost a year. The quest for the best bullets continues, but at press time Cor Bon was offering three effective loads.

The "light" load is a 275-grain Barnes X copper hollowpoint bullet. Muzzle velocity is 1665 fps and it produces 1668 ft.-lb. of energy. It is more than adequate for any game up to and including elk.

A 400-grain jacketed softpoint at 1675 fps and 2500 ft.-lb. of energy is available for larger game.

Those heading to Alaska, Africa or even Jurassic Park will want the 440-grain hard-cast lead, gas checked, flat point load. At 1625 fps and 2580 ft.-lb. of energy, it will handle anything a handgun hunter is likely to pursue.

A 385-grain flat based spitzer load was to be available by press time. Cor Bon says this may be the best all-around load for the 500 S&W.

Additional loads may well be more powerful. There is enough room in the cartridge case and revolver cylinder to handle bullet weights up to 500 grains, which will make the Model 500 suitable for any game animal on Earth.

GL-06 40mm grenade launcher (Switzerland)

GL-06 grenade launcher is a dedicated stand-alone shoulder-firing weapon, intended for military and police applications. Designed by well-respected Swiss arms-making company Brügger & Thomet AG, GL-06 is already in use with certain European military Special Forces groups. A special dedicated "less lethal" version of GL-06 is produced as LL-06. It must be noted that the only difference between GL-06 and LL-06 is the color of the frame - both weapons are fully capable of firing a complete range of 40mm x 46 munitions.

GL-06 grenade launcher with optional accessories such as Red Dot sight, forward grip and a tactical light

GL-06 grenade launcher with barrel opened up for loading

LL-06 - a dedicated less-lethal version of the GL-06, intended for police application, with array of available less-lethal and practice munitions


Caliber: 40x46mm low velocity
Type: single-shot 
Overall length: 590 / 385 mm (stock opened / folded)
Weight: 2,05 kg unloaded
Effective range: up to 300 m




It must be noted that GL-06 was born from recent request from police force of one of leading European nations, which sought to obtain a less-lethal weapon for anti-riot application, with particular need for pin-point accuracy at standoff ranges (beyond 40 meters for such scenarios) when firing impact rounds. B+T provided its client with both weapon and a special round, with added benefit of compatibility with wide array of lethal and less-lethal ammunition produced in 40mm low-velocity class. GL-06 is lighter and more compact than other stand-alone weapons of the same class (such as US M79 or German HK 69), yet it is capable of great accuracy, tactical flexibility and has good ergonomics.

GL-06 grenade launcher is a single shot weapon, with rifled tip-up barrel. For loading and unloading, rear part of the barrel is tipped up; therefore, rounds of any conceivable length can be easily loaded and extracted without problems. Barrel opening is assisted by special spring, thus speeding-up the reloading process. The barrel lock levers are fully ambidextrous and located in front of trigger guard, within the reach of the index finger. Trigger is of Double Action Only type, with concealed hammer. Additional manual safety is provided in form of the cross-bolt button located on the receiver above the pistol grip. GL-06 is provided with integral open sights (with adjustable diopter-type rear sight), and an integral Picatinny type rail on the barrel, which permits installation of many types of sighting equipment. Three additional accessory rails are installed on the short forend, below the barrel. GL-06 is fitted with side-folding butt, made of durable polymer, and is equipped with sling attachment points.

Mark 153 (Mk.153) SMAW rocket launcher (USA)

The SMAW (Shoulder-launched Multi-purpose Assault Weapon) has been developed by early 1980s by McDonnel Douglas corporation especially for US Marine Corps (USMC), which required lightweight, one-man portable multipurpose weapon, capable to defeat light armor, enemy bunkers and other reinforced positions. Currently manufactured in USA by Talley Defence Systems, the SMAW is in service with USMC since 1984. Known in service as Mark 153 Model 0 (Mk.153 Mod. 0) SMAW rocket launcher, it can fire a variety of ammunition, intended against light armor such as armored personnel carriers, enemy bunkers etc.

SMAW launcher in ready to fire configuration, with HEDP rocket in canister attached to the launcher

SMAW rockets and loading canisters (containers): left HEDP (dual purpose), right HEAA (anti-armor) 

SMAW launcher in action. The barrel and mechanism of spotting rifle are clearly visible, attached to the right side of the launcher.

SMAW 9x51mm Mark 217 Mod 0 spotting rifle cartridge

Caliber: 83 mm rocket + 9mm spotting rifle
Type:  rocket 
Overall length: 825 mm (launcher), about 1370 mm (ready to fire w. HEDP round) 
Weight: 7.52 kg unloaded launcher plus 4.3 to 6.9kg rocket in canister.
Effective range: up to 250 m (500m max)
Armor penetration: HEAA ~ 580-600mm (23-24") RHA; HEDP 25mm (1") RHA or 30cm (12") brick wall or 20cm (8") concrete wall

SMAW is a shoulder-fired, reusable rocket launcher that consists of a launch tube made of epoxy and fiberglass, with attached firing unit, 9mm spotting rifle, and sight bracket. Firing unit has dual grips, manual safety, and fire selector that allows to fire either a spotting rifle or a loaded rocket. Spotting rifle is  is ballistically matched to all rockets. It is loaded with special ammunition and fires from special 6-round magazines. Spare magazines are clipped to each rocket container. Once operator roughly aimed the unit, using either telescope or night sight, or backup open sight, he starts to fire spotting rifle until rounds are hitting the intended target. 9mm bullets provide a visible trace up to 500m range, so operator can check his aim, and once on target, he then switches to rocket and launches it. SMAW launcher can be fired from the shoulder, using dual grips and shoulder rest, or from the ground, using folding bipods located near the center of mass, next to the shoulder rest.

All types of rockets are supplied in disposable, sealed plastic containers, which are clipped to the rear part of the launcher. Once rocket is fired, empty container is detached from the launcher and discarded. Rockets have caliber of 83mm, and are stabilized in flight using spring-open switchblade-type stabilizations. Standard types of rockets are: Mk.3 HEDP (High Explosive Dual Purpose) weighting 4.35kg (5.9kg in container), Mk.6 HEAA (High Explosive Anti Armor) weighting 4.4kg (6.2kg in container), CPR (Common Practice - training), FTG (Follow-Through Grenade with dual warhead - first that penetrates barrier, and second that follows through the hole and explodes inside)  weighting 5.2kg (7.1kg in container), and CS (Confined Space with HEDP warhead - creates no backblast and can be fired from confined spaces such as rooms in building) weighting 6.9kg (9.1kg in container). The most recent (2003) addition to the range of SMAW rounds is Mk.80 rocket, known as NE (Novel Explosive, basically a thermobaric HEDP warhead).

It is worth to note that both self-loading (semiautomatic) Spotting Rifle and a 9x51mm spotting ammunition were developed in UK by Royal Ordnance.

Heckler & Koch HK XM25 IAWS

The Heckler & Koch XM25 is currently being field-tested with full deployment expected in 2012 if all goes as planned.

The futuristic Heckler & Koch HK XM25 IAWS (Individual Airburst Weapon System) is a semi-automatic, multiple-shot, shoulder-fired 25mm grenade launcher categorized as an "airburst weapon" system designed to neutralize out-of-view targets. The term airburst is derived from the launcher's use of fuze delayed detonated munitions which allow for a higher kill probability. Initial prototypes were handed over to the United States Army for field-testing in April of 2005. By the middle of 2009, field tests in combat zones from Iraq to Afghanistan were taking place. The project - barring any setbacks - should see fielding in production form sometime in 2012.

The general basis of the XM25 is in its rangefinding and delayed munition detonation capabilities. The operator activates the laser rangefinder and determines the distance to a target or target area. Once determined by the rangefinder, the operator then has the freedom to "fine-tune" the detonation delay of the projectile before firing by adding to - or subtracting - distance. The chambered grenade is "imprinted" with the calculated distance via a microchip fitted into every 25mm projectile. The operator pulls the trigger and propels the grenade onto its flight path. The grenade then automatically follows through by calculating how many rotations have occurred since it was launched from the rifled barrel. Once the pre-set range is reached, the grenade detonates itself at or in the area of the target. In essence, it is a "smart" weapon - though still requiring user input, it handles a great deal of the actual work post-fire. A first-kill probability is noted to be very high at least against target mannequins.

The XM25 is designed in a "bullpup" configuration, meaning that the magazine and applicable feed system is mounted to the rear of the pistol grip, trigger group and receiver. This provides for a stable hold when up against the operators shoulder as it necessitates a larger and heavier stock. The specialized optical system -the Target Acquisition Fire Control System - is fitted above the receiver. The forward portion of the weapon body is contoured to fit nicely in the free hand of the operator to further assist in bracing the weapon. The pistol grip features an integrated guard running forward of the trigger to the base of the pistol grip. Overall weight (6.3 kilograms) is said to be comparable to an M16 assault rifle with the 40mm grenade launcher attachment. Range is listed at 500 meters for point targets and up to 1,000 meters for ranged area targets. In some ways, the XM25 is similar in appearance to another -albeit ill-fated- Heckler & Koch / Alliant Techsystems joint development, the XM29 OICW.

The XM25 makes use of a low-velocity 25x40mm grenade munition. The launcher can fire this caliber of grenade in varying forms including a two-warhead high-explosive round (HEAB - High-Explosive Air Bursting), a flechette-laden (arrow) round and a thermobaric round (useful in confined spaces such as caves). Additionally, there will be standard training rounds as well as non-lethal rounds. The weapon fires from a 4-round oversized magazine fitted to the rear of the weapon.

The heart and soul of the XM25 is its Target Acquisition Fire Control System (TAFCS). This complex piece of equipment (developed by L-3 Communications Brashear) allows the XM25 operator to engage and fire on targets in day or night (the latter via thermal imaging), in adverse weather conditions and against targets in defilade - that is, hidden from view in a ditch or ravine. Similarly, the weapon will give the US soldier the capability to engage targets inside of buildings, firing from windows. The soldier need only his weapon to calculate the distance past the window frame, fire the XM25 and have the grenade detonate once it is inside the room, hopefully defeating the enemies within - all this with little damage to the building's major internal substructure. The laser rangefinder is activated through a button found along the front side of the XM25's trigger guard. The trigger guard also has the controls to fine-tune the range, adding or subtracting meters to the chambered grenade "on-the-fly". Aiming is via an adjusted crosshair aim point in the optical lens where the recorded target distance is also displayed. The fire control system evaluates the current air temperature and pressure and takes into account the inherent ballistics of the 25mm round for the presented range.

The US Army is intending to purchase some 12,500 M25 systems beginning in 2012 in an effort to field at least one unit with each of its infantry squads as well as for its Special Forces detachments. Primary development of the weapon has been handled by Heckler & Koch GmbH of Germany and Alliant Techsystems of Minnesota, USA.

The first successful test fire of the XM25 by a US soldier occurred at Aberdeen Test Center in Maryland on August 11th, 2009. Testing has shown results on practice targets to be up to 300% greater than that of current squad level weapons tasked to do the same job. Training on the XM25 has also been noted as swift with new XM25 operators being made ready to fire the weapon within five minutes time.

In theory, the XM25 is one of those "mouth watering" warfare devices (such as the Lockheed F-22 Raptor) that could very well change the face of the modern battlefield if it is put into actual practice. The "gun-and-hide" tactics of Al Qaeda's strategy guide will need to be rewritten.

 

M202 M202A1 M202A2 FLASH multishot rocket launcher / flamethrower (USA)

The M202 multishot rocket launcher evolved from XM191 multishot rocket launcher, that was extensively combat tested by US Army in Vietnam during late 1970s. The M202 is very similar to XM191 although it appears that its rockets were loaded with different incendiary agent - TPA rather than Napalm. It is also believed that XM191 was developed as a multipurpose weapon, capable of firing not only incendiary, but also 66mm HEAT rockets, compatible with that of M72 LAW lightweight antitank weapon. The M202, however, was issued only with one type of ammunition - the M74 incendiary rockets.

Clip of four M74 incendiary rockets for M202 FLASH grenade launcher / flamethrower (drawing)

Drawing of the M74 incendiary rocket in flight configuration (with tail fins extended)

US soldier aims the M202A1 FLASH grenade launcher / flamethrower, possibly during the Vietnam war

M202A1 FLASH grenade launcher less clip, with covers opened

US soldier aims the M202A2 FLASH grenade launcher / flamethrower, circa 1991

Caliber: 66 mm
Type:rocket
Overall length: 686 mm empty launcher, 883 mm loaded with clip
Weight: 5.22 kg unloaded, 12 kg loaded with clip of 4 rockets
Effective range: up to 200 m (750 m maximum)



In theory, the M202 was an impressive weapon with significant combat capabilities - it had long range (compared to earlier flamethrowers), it allowed for relatively rapid fire and high maneuverability, its physical and psychological effect on unprotected infantry and military vehicles was significant to say the least. However, it appears that M202 ammunition had some flaws (most probably due to poor quality control or design flaws), which resulted in self-ignition of warheads during loading of the weapon. Not surprisingly, such disastrous events made the M202 less than popular among the troops, and most M202 launchers were put into storage during late 1980s, although some launchers were observed during training of US and allied troops through early 1990s.

It must be noted that M202 made its biggest impact not on the battlefields but rather on cinema screens, when it was featured in the "Commando" movie (1985), starring Arnold Schwarzenegger. In this movie the M202 was used to blow up the police truck and free the Schwarzenegger's character, although in real life this would be the last scene of the action, with main character quickly burned to death inside scorched truck (the M74 rocket generated fire as hot as 1800-2200C for several minutes).

The M202 multishot rocket launcher is a four-barreled re-usable smoothbore weapon which is loaded with a clip with factory-loaded M74 rockets, pre-loaded into separate aluminum tubes that are assembled together to form a single 4-shot clip. The clip is attached to the rear of the launcher and each loaded tube forms an extension to the barrel. Once clip is loaded and fixed to the weapon, launcher can be fired up to 4 times, with practical rate of fire as high as 1 round per second. Once all rockets are fired, the empty clip is detached and discarded. During storage and transportation the M202 launcher is closed at front and back with two hinged covers, which shall be unlocked and opened before loading and firing. The front cover has a dual-purpose handle, which is used for carrying the launcher in vertical position, and is used as a forward grip in firing position. Firing controls include folding pistol grip under the barrel cluster, and folding collimating sight on the left side of the weapon. 66mm rockets use solid fuel engines, switch-blade type folding stabilizator fins, and a warhead loaded with some 0.6kg of self-igniting triethylaluminum (TEA), a gel-like substance. Since the M202 is a rocket launcher, upon firing it produces a dangerous backblast zone about 15 meters long.

XM307 ACSW Advanced Crew-Served Weapon / automatic grenade launcher (USA)

Picture 1: XM307 ACSW grenade launcher, front view

Picture 2: XM307 ACSW grenade launcher, rear view

Picture 3: XM307 ACSW grenade launcher on field trials

Caliber: 25x59mm
Type: gas operated, belt fed automatic grenade launcher  
Overall length: 1328 mm
Weight: 22.7 kg complete with tripod mount and sight / fire control unit 
Effective range: up to 2000 m against point targets, 3600 m maximum
Rate of fire: 250 rounds per minute

The origins of the XM307 Advanced Crew Served Weapon (ACSW), also known as XM307 25mm Airbursting Weapon System, lie in the several military documents, published in USA during late 1980s. These documents stated that current small arms have reached its peak in development, and the only currently possible way to increase combat effectiveness and single-shot lethality of such weapons is do develop new guns that will fire air-bursting munitions with programmable fuses. Following these conclusions, US Army initiated development of several so-called Objective weapons; two most famous of these were XM29 Objective Individual Combat Weapon (OICW) and XM307 Objective Crew-Served Weapon (OCSW), currently renamed to Advanced Crew-Served Weapon (ACSW). After much development, the prime contractor for ACSW program was selected as General Dynamics Armament and Technical Products (GDATP). The development team for ACSW also includes General Dynamics Ordnance and Tactical Systems (air-bursting ammunition), Kaman Dayron Inc (programmable fuze) and Raytheon (computerized fire control system). First demonstrated in around 1999 as 25mm OCSW, at the present time (early 2006) the XM307 ACSW is on advanced stages of development, with several prototypes already tested with live ammunition, including air-bursting rounds. Initial plans called for first US Army units to be equipped with 25mm M307 ACSW weapons by 2008; M307 shall replace in service the older weapons like Mk.19 Mod.3 40mm grenade launchers and .50 caliber M2HB machine guns. For added versatility, XM307 can be easily converted to fire .50 caliber machinegun ammunition (12.7x99) with replacement of just 5 parts.

The key to greatly increased combat effectiveness of ACSW system is programmable air-bursting ammunition, which will be used in conjunction with electronic fire control unit. This ammunition will allow to precisely engage enemy personnel in open or in defilade, without the need for direct impact in the target area. Other types of ammunition proposed for XM307 ACSW are HEAT (with required armor penetration up to 5cm / 2in), less-lethal (with tear gas for peace-keeping applications) and training rounds with dummy warheads.
It is obvious that by the year 2008 the XM307 will enter into strong competition with several 40mm air-bursting weapons such as Mk.47 Striker 40, and the outcome of this competition is hardly predictable, as either system has its own merits and downsizes. ACSW is certainly lighter, fires lighter ammunition (allowing to carry more ammo in the same weight), and has longer range. 40mm weapons fire bigger warheads and can use huge stocks of already existing and well developed NATO-standard ammunition of various types, including point-detonating FRAG, HEDP, AP, less-lethal and many others.

XM307 Advanced Crew Served Weapon is gas operated, rotating bolt locked weapon that uses differential recoil system for decreased peak recoil. XM307 is belt fed weapon that fires from open bolt. The differential recoil system means that barrel and bolt group are allowed to recoil within the receiver casing together, against the recoil springs. When weapon is cocked for first shot, bolt is locked open and the entire barrel/bolt group is carried rearwards and also locked there. Upon the pull of the trigger both barrel group and the bolt inside it are released, and the bolt loads the round and locks it in chamber while barrel still moves forward; firing pin is then released immediately, and the recoil from the discharge first has to arrest the forward movement of the barrel group, and then throws it backward with less force than it would in the traditional system with fixed barrel. The belt feed and bolt cycling are operated by conventional gas action. The fire control unit includes zoomable day and night vision channels that output the sight picture to the small display at the rear of the sight. Integral laser range-finder allows for precise range measurement, necessary for automatic point of aim correction and for programming of the air-bursting fuses. XM307 weapon is fitted with dual, ergonomically shaped spade grips with triggers and fire and sight control buttons. Additional buttons are located at the rear of the sight / fire control unit, below the eyepiece. In standard applications, XM307 can be used either on lightweight infantry tripod, or on vehicle mounts, manually or remotely controlled. For vehicular applications, GDATP will develop the dual feed option, which will allow to select the type of ammunition (anti-personnel HEAB or armour-piercing) at the instant before firing.

 

Mk.47 (Mark 47) Striker 40 automatic grenade launcher / machine gun (USA)

Picture 1: Mk.47 mod.0 Advanced Lightweight Grenade Launcher (ALGL) on standard tripod

Picture 2: Mk.47 mod.0 automatic grenade launcher, close-up view

Picture 3: Mk.47 mod.0 automatic grenade launcher, close-up view from the rear; note screen of electronic sighting / fire control unit

Picture 4: Mk.47 mod.0 automatic grenade launcher on field trials

Caliber: 40x53mm High Velocity
Type: short recoil operated, belt fed automatic grenade launcher  
Overall length: 940 mm
Weight: 18 kg gun body; 41 kg complete with Mk.108 tripod and AN/PWG-1 video sight 
Effective range: up to 1700 meters against point targets, up to 2200 m maximum
Rate of fire: 225-300 rounds per minute

The development of the more lightweight and effective weapon which could replace venerable Mk.19 Mod.3 automatic grenade launcher in US and foreign service, has been initiated by Saco Defense Company (now General Dynamics Armament and Technical Products - GDATP) during late 1980s.First prototypes of the new weapon appeared by mid-1990s, and in 1995 US DoD approved the industry team which then consisted of Saco Defense (now GDATP) as a weapon producer and system integrator, and Raytheon as a provider of advanced electronic sighting and fire control equipment. Later on, team was joined by Norwegian NAMMO Oy company, which develops the advanced, air- bursting 40mm ammunition for new weapon. In the year of 2003, US Special Operation Command (USSOCOM) adopted the GDATP Striker 40 40mm automatic grenade launcher as Mark 47 model 0, complete with its new tripod mount and AN/PVG-1 Lightweight Video Sight developed by Raytheon. These weapons now (February 2006) are in limited service with US Special Operation forces in Afghanistan and Iraq, and also are being considered for adoption by US Marine Corps. Mk.47 grenade launchers are compatible with full spectrum on NATO-standard 40mm high velocity ammunition; advanced air-bursting ammunition with programmable fuses is being developed for this weapon. Once this ammunition will be available, the Mk.47 / Striker 40 weapon system will provide serious and more cost-effective alternative to the much-discussed 25mm XM307 ACSW weapons now in development.

Mark 47 Model 0 (mk.47 mod.0) automatic grenade launcher is short recoil operated, locked breech weapon that fires from closed bolt for improved first-shot hit probability. Weapon is air-cooled and belt fed, using standard disintegrating belts, same as Mk.19 Mod.3 launcher. Standard belts are supplied in 32 or 48 round boxes. Weapon is equipped with newly developed Mk.108 mod.0 tripod with T&E mechanisms and brake that allows to lock weapon on pre-selected target spot. The key member of the Striker 40 system is the AN/PVG-1 Lightweight Video Sight (LVS), which offers 3X magnification TV view on target, combined with laser range finder and ballistic computer; sight also has interface connectors that allow to link it to optional thermal night sighting equipment which can be installed on the weapon; once the night sight is connected, operator can select TV or thermal picture via the single button. The LVS allows to accurately measure the range to the target then aim the gun accurately for high first shot hit accuracy. LVS is installed on the right side of the weapon, and is controlled by the buttons and four-position "joystick" located at the rear of the receiver, between and above spade grips.