M79 grenade launcher

Launcher, Grenade, 40 mm, M79
M79 with the leaf-type sight unfolded.
Type	Grenade launcher
Place of origin	United States
Service history
In service	1961–present
Used by	See Users
Wars	Vietnam War Cambodian Civil War Falklands War Bougainville Civil War Afghan War Iraq War Cambodian–Thai border stand-off 2010 Burma border clashes
Production history
Designer	Springfield Armory
Designed	1953–1960
Manufacturer	Springfield Armory, Action Manufacturing Company, Exotic Metal Products, Kanarr Corporation, and Thompson-Ramo-Wooldridge
Produced	1961–1971
Number built	350,000 (U.S. only)
Specifications
Weight	2.93 kg (6.45 lb) loaded 2.7 kg (5.95 lb) empty
Length	73.1 cm (28.78 in)
Barrel length	35.7 cm (14 in)
Cartridge	40×46mm grenade
Action	Break-action
Rate of fire	6 rounds/min
Muzzle velocity	76 m/s (247 ft/s)
Effective firing range	350 m (383 yd)
Maximum firing range	400 m (437 yd)
Feed system	breech-loaded
Sights	Blade and leaf type

The M79 grenade launcher is a single-shot, shoulder-fired, break-action grenade launcher that fires a 40×46mm grenade, which uses what the US Army calls the High-Low Propulsion System to keep recoil forces low, and first appeared during the Vietnam War. Because of its distinctive report, it has earned the nicknames of "Thumper", "Thump-Gun", "Bloop Tube", and "Blooper" among American soldiers;^[1] Australian units referred to it as the "Wombat Gun".^[2] The M79 can fire a wide variety of 40 mm rounds, including explosive, anti-personnel, smoke, buckshot, flechette (pointed steel projectiles with a vaned tail for stable flight), and illumination. While largely replaced by the M203,^[3] the M79 has remained in service in many units worldwide in niche roles.

History

The M79 was a result of Project Niblick, an attempt to increase firepower for the infantryman by having an explosive projectile more accurate with further range than rifle grenades, but more portable than a mortar. Project Niblick created the 40 x 46 mm grenade, but was unable to create a satisfactory launcher for it that could fire more than a single shot. One of the launchers at Springfield Armory was the three-shot "harmonica" T148 (not to be confused with the later, underbarrel XM148), which did see some limited production and fielding in Vietnam, but problems with the three-round magazine prevented widespread acceptance. The other design was a single-shot break-open, shoulder-fired weapon, the S-3. This was refined into the S-5, which resembled an oversized single-barrel shotgun. Unable to solve the problems with the multi-shot T148 launcher, the Army adopted the S-5 as the XM79. With a new sight, the XM79 was officially adopted as the M79 on December 15, 1960.^[4]

In 1961, the first M79 grenade launchers were delivered to the US Army. Owing to its ease of use, reliability, and firepower, the M79 became popular among American soldiers, who dubbed it "the platoon leader's artillery".^[5][6] Some soldiers would cut down the stock and barrel to make the M79 even more portable.^[7]

The M79 saw combat in the Vietnam War beginning in the early days, when M79 Grenadiers assigned to major Army divisions first arrived to see combat in Vietnam in 1965, including the 1st Cavalry Division, the 1st Infantry Division, the 101st Airborne Division, and the 173rd Airborne Brigade. M79s were assigned to the specialist 4 grenadier in both 4-5-man fire teams organic to an Army rifle squad headed by a squad leader. The Marines assigned one grenadier to their three-fire team 14-man rifle squad.

However, its single-shot nature was a serious drawback. Reloading after every shot meant a slow rate of fire and an inability to keep up a constant volume of fire during a firefight. This led the Navy to develop the China Lake Grenade Launcher, which a were produced for deployed SEAL Teams. For close-in situations, the minimum arming range (the round travels 30 meters to arm itself) and the blast radius meant a grenadier had to use his .45 cal. pistol, or fire and hope that the grenade acted as a giant slow bullet. Special grenades for close-in fighting were created to compensate, though a soldier was not always able to load one in the heat of battle. Moreover, its size meant that a soldier with an M79 could be only a grenadier, and when he used up his limited rounds he had only a pistol to use in a firefight. Underbarrel grenade launchers, such as the XM148 and the M203, where the grenade launcher attaches to an M16 rifle, were developed during the Vietnam War, allowing the grenadier to function also as a rifleman. Some grenadiers opted to carry a slung M16 rifle in lieu of a pistol.

The XM148 was plagued with problems and the project was dropped. The M203 was a success, and was standardized in 1969;^[8] it had replaced the M79 by the end of the war, though M79s were still used in Reserve and National Guard units.

Some US Navy SEALs and Army Special Forces in Iraq have been seen using the M79 in recent years, due to its greater accuracy and range compared to the M203 (350m effective versus 150 m effective on the M203). The M79 has seen notable limited use during Operation Iraqi Freedom, such as for clearing IEDs.^[9]

Design

M79

Visually, the M79 grenade launcher resembles a large bore, break-action, sawed-off shotgun,^[10] and is simple in design, having only five major parts: a receiver group, a fore-end assembly, a barrel group, a sight assembly, and a stock. The fore-end assembly beds the barrel to the receiver. The stock is made out of wood or fiberglass. A rubber pad affixed to the buttstock absorbs some recoil. The front sight is a fixed blade. The rear sight on the M79 is a folding ladder-style leaf-type sight. When folded, the leaf sight acts as a fixed sight for close range. A grenadier may simply point and shoot with high accuracy. When unfolded, the leaf-type sight could be adjusted for ranges from 75-meters to 375-meters, in 25-meter increments. Additionally, Appendix A of U.S. Army field manual for the M203 includes instructions for attaching the M16 rifle grenade sight to the M79's stock and marking the sling for indirect fire at elevations greater than 40°.

While not a manufacturer, Milcor/Mechem of South Africa do re-manufacture M-79 grenade launchers to more modern standards. They replace the leaf sight with an optical one and replace the wooden stock with a modified R-4/R-5 stock.

Operation

M79 (right) with an FN minimi

M79 being set up for display

The M79 is easy to operate. To load, the grenadier pushes the barrel locking latch on the receiver group to the right. Gravity will pull down the barrel, breaking it open, and exposing the breech. The hammer is cocked when the breech is opened. A round then may be loaded. The break action must then be closed manually. Closing the breech will cause the barrel locking latch to return to center. The safety must then be pushed to the forward position in order to ready the weapon for firing.

Ammunition

Many different ammunition types were produced for the M79 (and subsequently for the M203), outside of the smoke and illumination rounds three main types emerge: explosive, close-range, and non-lethal crowd control. The break-open action of the M79 allows it to use longer rounds that the standard M203 cannot use without some difficulty.

Explosive

The M406 40 mm HE (high explosive) grenades fired from the M79 travel at a muzzle velocity of 75 meters per second. The M406 contained enough explosive to produce over 300 fragments that travel at 1,524 meters per second within a lethal radius of 5 meters. This round incorporated a spin-activation safety feature which prevents the grenade from arming while still within range of the shooter; it armed itself after traveling a distance of about 30 meters. Even though the round would not arm at point blank ranges, the round usually did not have enough kinetic energy to kill although it sometimes penetrated the abdomen or caused large hematomas.

Close range

A less-lethal round is loaded into an M79

For close range fighting, two styles of M79 rounds were developed. The first was a flechette or Bee Hive round (so named for the sound the flechettes made while in flight)^[11] that fired 45 10-grain steel flechettes. Flechettes proved to be ineffective because they would often not hit point-first and penetrate. Instead they would hit sideways and bounce off. About 1966, this was replaced by the M576 buckshot round. Containing twenty 24-grain metal pellets^[12] (M576E1) or twenty-seven 24-grain metal pellets (M576E2), this round could be devastating at close ranges. However, as range increased, the shot spread out so rapidly as to be ineffective. The M576E2, despite the greater number of shot, was less effective at range than the M576E1, because its shot spread out much more quickly and could completely miss the target.

Non-lethal

The M79 has been used extensively also for crowd control purposes where it is desirable to have a weapon dedicated solely to non-lethal force. The three common less-lethal rounds are the M651 CS gas, the M1006 sponge grenade, and the M1029 Crowd Dispersal rounds.

Users

Australia[2]  Brazil: Used by the Brazilian Army.[13][14]  Cambodia[15][16]  Chad[13]  Colombia[13]  Costa Rica[13]  Dominican Republic: Used by the Dominican Army.[13]  El Salvador[13]  Eritrea[13]  Ethiopia[13]  Fiji[13]  Greece[13]  Guatemala[13]  Haiti[13]  Honduras[13]  Indonesia[13]  Iran[13]  Ireland[13]  Israel[13]  Jamaica: Jamaica Defence Force.[13][17]  Jordan[13]

Soldiers of the Royal Thai Army Volunteer Regiment (Queen's Cobras) conduct a search and sweep mission in Phuoc Tho, 1967  Kenya[13]  Kurdistan – Peshmerga  Lebanon[13]  Malaysia[13]  Myanmar[13]  Nicaragua[13]  Oman[13]  Paraguay[13]  Philippines[13]  Portugal[13]  Saint Vincent and the Grenadines[13]  Saudi Arabia[13]  Somalia[13]  South Korea: Manufactured by S&T Daewoo under license as KM79.[18]  Spain[13]  Taiwan[13]  Thailand[13]  Turkey[13]  United States[13]  Vietnam: Locally produced (at Factory Z125) as M79-VN, with plum-red synthetic stock and optical sight.[19]  Yemen[13]

See also

• China Lake Grenade Launcher
• HK69 Grenade Launcher
• EAGLE grenade launcher
• B&T GL-06 Grenade Launcher
• XM174 grenade launcher
• M320
• FN40GL EGLM
• Fort-600 grenade launcher
• Mk 19 grenade launcher

References

1. As well as some variants on these:
   • "Blooper" and "Thumper", according to Rottman, Gordon L. (2005). US Army Infantryman in Vietnam 1965–73. Osprey. p. 31. ISBN 1-84176-887-1.
   • "Thumper", "Blooper Gun", "Thump Gun" and "Bloop Tube" in Clark, Gregory R. (1990). Words of the Vietnam War. McFarland. p. 303. ISBN 0-89950-465-5.
2. McKay, Gary (1998). Delta Four: Australian Riflemen in Vietnam. Allen & Unwin. p. 293. ISBN 1-86448-905-7.
3. M203 40mm Grenade Launcher
4. Dockery, Kevin (December 2004). Weapons of the Navy SEALs. New York City: Berkley Publishing Group. pp. 372–374. ISBN 0-425-19834-0.
5. Clark II, Clair William (2002). Land, Sea and Foreign Shore: A Missileer's Story. Xlibris. p. 77. ISBN 1-4010-6380-2. [The M79] was very popular because it was fun and easy to shoot[...] This popular weapon was dubbed "the platoon leader's artillery." It was a deadly little dude.
6. Stanton, Shelby L. (1987). Anatomy of a Division. p. 198. ISBN 0-89141-259-X. The M79 was popular and handy, being both thoroughly reliable and virtually maintenance-free.
7. Halberstadt, Hans (2004). War Stories of the Green Berets. Zenith Press. p. 231. ISBN 0-7603-1974-X.
8. Rottman 2005, p. 31.
9. "Marines test 'blooper' against roadside bomb threat". Retrieved 23 November 2014.
10. Clark 2002, p. 77. "It looked like a small, pregnant, breech loading, sawed off shotgun."
11. "War Stories 6". Retrieved 23 November 2014.
12. "40mm Low-Velocity Grenades". Retrieved 23 November 2014.
13. Jones, Richard D. Jane's Infantry Weapons 2009/2010. Jane's Information Group; 35 edition (January 27, 2009). ISBN 978-0-7106-2869-5.
14. http://www.exercito.gov.br/01inst/armtmuni/lancagrana.htm
15. "Small Arms Survey - Working Papers" (PDF). 8 November 2012. Retrieved 23 November 2014.
16. "Misunderstanding leads to Thai-Cambodian border clash: Thai, Cambodian armies". Retrieved 23 November 2014.
17. ncoicinnet. "Web Site of the Jamaica Defence Force". Retrieved 23 November 2014.
18. Jane's Infantry Weapons 1997–98 (23rd ed.). Coulsdon, UK: Jane's Information Group. p. 242. ISBN 0-7106-1548-5.
19. "Việt Nam sửa chữa súng phóng lựu Mỹ" (in Vietnamese). 2012-12-08. Archived from the original on 2012-11-03. Retrieved 2014-04-29.

External links

• Gary's U.S. Infantry Weapons Reference Guide
• US Army Field Manual 3–22.31 Appendix A
• The short film STAFF FILM REPORT 66-12A (1966) is available for free download at the Internet Archive
• The short film STAFF FILM REPORT 66-17A (1966) is available for free download at the Internet Archive