by DAN SHEA


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     Karachi, Pakistan;
     -------1979:
     Report of Agent ---:
     Attn. - General----:
     Sir,
     I have just returned to "base," fresh from the Afghani-Soviet front.
     The Mujahideen are fierce fighters and are holding their own when not
     outright advancing against the Soviet forces. Our small arms packages
     have helped them very much - these are a tough bunch of warriors.
     They "improvise, overcome, and adapt" in even the most adversarial
     conditions. The Soviet weaponry that they are having the most trouble
     against are the Hind helicopters, which we anticipated. (The few
     surface-to-air units that "accide ntally" made their way to the
     Mujahideen are causing the Hind pilots to hold back a little - they
     quickly learned that these mountain tribesmen may ride horses, but
     they can effectively use any modern technology that is weapons
     related!) On a more disturbing note - reports that the new Soviet
     AGS-17 30mm is being used to a devastating effect against the
     Mujahideen are true....The fully automatic grenade launcher is firing
     antipersonnel burst rounds, and it rules the battlefield wherever i t
     is used. We have been unable to advise an effective defense against
     the AGS-17 and would consider it a priority to get any input from the
     Infantry School or other sources on how to counter this weapon.
     Sincerely,
     -----

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During the Vietnam War, there were many new weapons ideas tested. The advent of
the individual soldier carrying a grenade launcher (M79 40mm) was modified by
trying to make every rifleman into a grenadier with the M203 40mm. Many of the
military planne rs tried to find a method of utilizing the massive
antipersonnel firepower of the 40mm grenade in a full-auto mode. Helicopters
were armed with pods that had miniguns and 40mm launchers that utilized higher
pressure rounds than the M79 ammo.

Chinook helicopters and PBR's (Patrol Boat, River) were armed with a
crank-fired, cloth belt-fed unit that fired the low pressure M79 ammo. (I have
located one of these and I am trying to get it so I can do an article on it.)
For ground use, Colonel Ge orge Chinn (author of the five-part book, The
Machine Gun) started work on the MK19 Mod 0 at Naval Ordnance in Louisville,
Ky. in 1966. By 1968, there were test models in use. There were a lot of parts
to the Mod 0 as it was originally fielded, and the re ports came back that it
was a "low reliability-high maintenance" unit.

Between 1971 and 1974, after a redesign to reduce parts and increase
reliability, a small quantity of the Mod 1 were issued to riverboat operations
in Vietnam. Being a mobile unit, with the firearm mounted and ammunition
available, the project met with more success. It was once again dropped as the
war in Vietnam ended.

In 1979, American undercover agents' reports came back from Afghanistan on the
devastating effect that the Soviet AGS-17 30mm had on the rebel forces. The
AGS-17 utilized "burst only" charges (antipersonnel), not "shaped"
(anti-armor). General Barry Mc Caffery, at the Infantry School in Ft. Benning
Georgia, received this intel and immediately started on a project to upgrade
the MK19 and bring it into inventory. Gen. McCaffery was an advocate of burst
mechanism munitions - it is well documented that a gr eater number of soldiers
are wounded or killed in battle by shrapnel than by bullets. It is largely
through his diligence that the current MK19 Mod 3 is used by today's forces. In
1982 the Navy lab called for the bidding for contract. Saco Defense, Royal
Ordnance, Ramo, and FN competed. Saco Defense won the contract and by 1985 they
were in production. (Export was restricted until 1991.)

The original U.S. users were the Marine Corps and the Navy SEALs. The Marines
started with mounts for the M151 Jeep and now have them on the Humvee. For the
AVV7, the 40/50 turret was made - either a .50 cal. M2-HB or the MK19 Mod 3 can
be used on it. Between 1988-90, the U.S. Army adopted the MK19 Mod 3, and Saco
Defense is the sole source for procurement.

The final Mod 3 has seen its parts reduced to a minimum...with that reduction,
reliability has gone way up. Many consider the MK19 Mod 3 to be the most
reliable firearm in the U.S. inventory. There are five major assemblies:
receiver assembly, feed sli de assembly and tray, top cover assembly, sear
assembly, and the bolt and backplate assembly. When I did the field strip and
reassembly at Saco, I was amazed at how easily everything went together. The
various groups, once subassembled, snapped back into position very quickly.
That counts in a combat weapon. (There are some good assembly/field strip hints
in the tech section of this article.)

There have been problems in the MK19 design that required the manufacture of
the receiver to be excruciatingly accurate. Military use requires that there be
parts interchangeability and ease of field maintenance. Saco utilizes the Zeiss
MC850 measuring device that compares over 160 characteristics on the MK19. The
MK19 receiver is the most complex component that the Zeiss company has ever
tested. Saco has two of these Zeiss MC850 measuring devices, in order to meet
government orders. The receiver is we lded out of forgings and stampings, and
every measurement must be precise. Like most government-contracted items, there
is a very precise requirement description. Saco Defense's MK19 meets or exceeds
the following as described in the MK19 catalog:

                                  TEST HISTORY

The MK19 Mod 3 grenade machine gun has an extensive test history. Developmental
testing was conducted in the early 1980s. Saco Defense and the United States
Government, beginning in 1983, has conducted extensive joint testing of the
MK19 Mod 3.

1983 PREPRODUCTION TEST

Ambient firing of two guns 20,000 rounds. Testing demonstrated 5,000 MRBS and
10,000+ MRBF. (MRBS-Mean Rounds Between Stoppages) (MRBF-Mean Rounds Between
Failures.)

1986 First Article Test

Ambient test of three guns firing 7,300 rounds. Demonstrated MRBS exceeded
5,300 rounds. MRBF exceeded 7,300 rounds

1988 Initial Production Tests

Guns successfully subjected to extreme environmental testing (sand, dust, mud,
icing and rain tests) in accordance with U.S. Department of Defense Test
Operating Procedure (TOP) 3-2-045 "U.S. Army Test & Evaluation Command Test
Operating Procedure s for Automatic Weapons, Machine Guns and Hand-Held
Shoulder Weapons."

Hot Testing at 68 degrees C, 10,000 rounds fired exhibiting MRBS of 1,100 and
MRBF of 10,000.

Cold Testing at -45 degrees C, 10,000 rounds fired demonstrating MRBS of 2,475
and MRBF exceeding 10,000.

In 1988, Saco Defense was contracted to improve the reliability and
maintainability of a new generation of the MK19 Mod 3. The improved MK19
currently in production remains fully interchangeable with the older version of
the MK19 Mod 3. Engineering imp rovements succeeded in improving the
reliability and performance of the gun.

1990 PreProduction Test

Ambient Firing of 20,000 rounds exhibiting an MRBS of 12,000 and MRBF of
12,000.

1991 First Article Tests

Ambient Firing of 50,000 rounds with MRBS of 8,350 and MRBF of 20,000+.

PERFORMANCE SPECIFICATIONS

The MK19 Mod 3 was developed and tested to meet the U.S. Government's stringent
operational performance requirements. These requirements provide the users with
a weapon that works consistently and reliably in demanding combat environments.

MK19 Mod 3 PERFORMANCE

All MK19 Mod 3s are thoroughly tested at Saco Defense's modern test facility.
Saco Defense conducts testing that insures all MK19s meet stringent U.S.
Government performance requirements of MIL-G-70790C.

Rate of Fire

325 rounds/minute minimum. All guns are measured during production acceptance
testing.

Targeting and Accuracy

3-round burst must strike a 14-meter square target at 1,000 meters. Production
acceptance based on all rounds striking 84-cm square target at a distance of 60
meters.

Belt Pull

MK19 must function with a 28-round hanging belt. Production acceptance based on
firing a 3-round belt with an equivalent 25-round weight hanging from the belt.

Remote Firing

Must operate with solenoid-controlled triggering.

MK19 Mod 3 RELIABILITY

Saco Defense and the U.S. Government conduct reliability tests of the MK19 Mod
3. These tests insure that Saco production meets all reliability requirements.
Reliability requirements are:

Barrel Life-10,000 rounds minimum

Receiver Life-25,000 rounds minimum

Stoppages-1,000 Mean Rounds Between Stoppage (MRBS) minimum

Failures-3,300 Mean Rounds Between Failures (MRBF) minimum

                                  Description

Basically, the MK19 Mod 3 40mm grenade launcher is a blowback-operated,
air-cooled, 40mm fully-automatic machine gun, firing 40mm grenades at a rate of
325 to 375 per minute. The effective range is 1500 meters with an extended
range out to 2500 meters. The firing system is "advance primer ignition,"
meaning that the firing pin will activate the primer 3/8" out of battery before
the round is fully chambered.

To operate, first point the weapon downrange. Then the feed box with belt is
placed in position on the mount, or next to it if you are using the M3 ground
mount (same as the M2-HB uses, with a different cradle). Make sure the bolt is
forward - don't sl am fire it - ease it forward. With the cover open, lay the
first round in the belt in the feed tray, female side of the link first - push
it across the first pawl - do not "roll" it, the pawl won't do its job. This
leaves the round between the first and s econd pawl. Make sure that the rounds
are straight and firmly seated. Move the feed slide assembly to the left, then
CLOSE THE TOP COVER. Grab the handles (palm down), rotate them to horizontal,
then pull the chargers sharply to the rear. Push them to for ward, and rotate
the handles up. To load your first round, place the safety in the "fire"
position, and press the trigger. The bolt will spring forward - you have now
loaded the first round onto the bolt face. Pull the chargers sharply to the
rear (Yes, y ou need to charge twice). You now have a live round on the bolt
face, to the rear, ready to fire. Push the charger handles forward and rotate
up, the MK19 will not fire if the charging handles are not in the "up"
position. Now, place the safety on "safe" unt il ready to fire.

Ammunition for the MK19 is different from that for the M79/M203. Most soldiers
refer to the M79 ammunition as "low pressure" and the MK19 as "high-pressure."
This is incorrect - they are both "low-pressure." The MK19 round is longer, and
develops more pressure than the M79 type, but it is still a low pressure round.
These rounds are two distinct types of ammunition- they ARE NOT INTERCHANGEABLE
BETWEEN THE M79/203, OR THE MK19! Low pressure 40mm functioning is described
quite well in the follo wing ammunition specification from Saco:

40MM, M430 HEDP (High Explosive, Dual Purpose) AMMUNITION

The M430 cartridge is a fixed round of ammunition designed for use against
personnel and lightly armored vehicles. The round consists of an internally
embossed one-piece steel projectile body which is press-fitted into an aluminum
bi-chambered cartridg e case assembly. The projectile body is fitted with a
metal rotating band. A PIBD fuze assembly with a Composition "B" spitback
charge and copper core liner is threaded into the open end of the projectile
cavity. The fuze assembly seals the front end of the projectile cavity which
contains the high-explosive shaped-charge.

The propelling charge is contained in a spherical high-pressure propellant
chamber with vent holes in the top sealed with a copper closing cup. The
chamber is sealed at the bottom with an aluminum base plug which is crimped
into the base of the cartrid ge case. There is a hollow chamber in the case
between the high-pressure chamber and the projectile base which acts as a
low-pressure chamber. A percussion primer is crimped into the center of the
case closing base plug.

The ammunition is loaded, assembled and packed in accordance with MIL-C-48684
(AR).

Functioning

The weapon firing pin strikes the percussion primer igniting the propelling
charge. Pressure, generated by the burning propellant in the high-pressure
chamber forces the expanding gases through the vent holes into the low pressure
chamber, and propels the projectile forward. The rotating band around the
projectile engages the barrel rifling which imparts a spin rate of 12,000 rpm
to the projectile.

When the projectile attains sufficient spin, arming begins. After the
projectile has traveled 18 to 30 meters from the launcher tube, the rotor is
locked in the armed position, and the fuze is armed. Upon impact with the
target, the firing pin is drive n into the detonator, which, in turn, initiates
the spitback charge, producing a jet which initiates the RDX explosive charge.
Concurrently, the RDX filler detonates, producing an armor-piercing jet of
molten metal and fragmentation of the projectile body .

The M430 ammunition is linked together with M16A2 links and packaged either in
the 48-round M548 container or the 32-round PA 120 container. The ammunition
should be ordered in multiples of full pallets to realize the most cost
effective shipping charg es."

Note that the factory description includes the description of an explosive jet
in the charge - this is considered a "shaped charge," capable of penetrating 2"
of armor.
There are other ammunition types available:
M-430 described above (yellow ogive, band is olive drab with yellow markings,
base is olive drab)
M-383 HE High Explosive (yellow ogive, band is olive drab with white markings,
base is olive drab)
M-385 TP target practice with inert projectile (blue ogive, band is blue with
white markings, base is blue)
M-918 TP target practice with 1 gram flash marking projectile
Dummy rounds - totally inert as well as a new tear gas round by Nico
Pyrotecnik.

In recent years, fire control has been the focal point of the Saco Team headed
by Kevin Sullivan. The original sighting system on the MK19 was essentially the
same ladder type sight as is on the M79. This system leaves a lot to be
desired. Saco focused on three basic problems: ability to mount an optical
sight, projectile drift, and use of the modern night vision devices, lasers and
range finders. The solution that they arrived at was a sight base that was
mounted off to the top right of the receiver, allowing for 30 degrees of
elevation with a full field of view. This also reduces "blooming" problems with
night vision, as well as heat rise off the barrel when using thermal sighting
devices. (The new flash suppressor had virtually eliminated the bloomi ng
problem.)

The base has an iron sight built in, and has a triangular base that allows for
a repeatable bore sight. The ring sight WC-30, which is the recommended system
for the MK19, is an optical day sight with graduations from 200 to 2000 meters.
Illumination i s by natural light or an attachable LED. It mounts on the Saco
sight base. Drift is compensated for in the WC-30 system - this is critical
considering that the 40mm round has a 60-meter drift to the right at 2000
meters! Up until the WC-30 system, the gun ner had to use "Kentucky windage."
This sight base will accept the TVS-13 laser, TVS-5 MILES, PAC4-B Laser
pointer, Aimpoint and F/C devices. The military required that the new sighting
system would accept and use current sighting devices. The U.S. Army B attle Lab
did extensive testing on the WC-30 system, and has endorsed it. The retrofit is
drilling four non threaded holes in the receiver.

___________________________________________________________________________

Millennium's End Stats

Speed: 11
Inherent Accuracy: 22
Attacks/turn: 4/12
Effective Range: 140 (max range 2 km)
Hands Required: 2
Ammo: 40mm grenade, belt (28)
Price: Unknown at this time, sorry.

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