Improvised Munitions Handbook (Improvised Explosive Devices or IEDs)

# Section 4
Mortars and Rockets

## 4.1 Recoilless Launcher

A dual directional scrap fragment launcher which can be placed to cover the path of advancing troops.

Materials Required
Iron water pipe approximately 4 feet (1 meter) long and 2 to 4 inches (5 to 10 cm) in diameter
Black powder (commercial) or salvaged artillery propellant about 1/2 pound (200 grams)
Safety or improvised fuse (section 6.7) or improvised electrical igniter (section 6.2)
Stones and/or metal scrap chunks approximately 1/2 inch (1 cm) in diameter – about 1 pound (400 grams) total
4 rags for wadding, each about 20 inches by 20 inches (50 cm by 50 cm)
Wire
Paper or rag

Note: Be sure that the water pipe has no cracks or flaws.

#### Procedure

1. Place propellant and igniter in paper or rag and tie with string so contents cannot fall out.

2. Insert packaged propellant and igniter in center of pipe. Pull firing leads out one end of pipe.

3. Stuff a rag wad into each end of pipe and lightly tamp using a flat end stick.

4. Insert stones and/or scrap metal into each end of pipe. Be sure the same weight of material is used in each side.

5. Insert a rag wad into each end of the pipe and pack tightly as before.

#### How to Use

1. Place scrap mine in a tree or pointed in the path of the enemy. Attach igniter lead to the firing circuit. The recoilless launcher is now ready to fire.

2. If safety or improvised fuse is used instead of the detonator, place the fuse into the packaged propellant through a hole drilled in the center of the pipe. Light free end of fuse when ready to fire. Allow for normal delay time.

Caution: Scrap will be ejected from both ends of the launcher.

## 4.2 Shotgun Grenade Launcher

This device can be used to launch a hand grenade to a distance of 160 yards (150 meters) or more, using a standard 12 gauge shotgun.

Materials Required
Grenade (Improvised pipe hand grenade, section 2.1, may be used)
12 gauge shotgun
12 gauge shotgun cartridges
Two washers, (brass, steel, iron, etc.), having outside diameter of 5/8 inch (1-1/2 cm)
Rubber disk 3/4 inch (2 cm) in diameter and 1/4 inch (6 mm) thick (leather, neoprene, etc. can be used)
A 30 inch (75 cm) long piece of hard wood (maple, oak, etc.) approximately 5/8 inch (1-1/2 cm) in diameter. Be sure that wood will slide into barrel easily.
Tin can (grenade and its safety lever must fit into can)
Two wooden blocks about 2 inches (5 cm) square and 1-1/2 inch (4 cm) thick
One wood screw about 1 inch (2-1/2 cm) long
Two nails about 2 inches (5 cm) long
12 gauge wads, tissue paper, or cotton
Adhesive tape, string, or wire
Drill

#### Procedure

1. Punch hole in center of rubber disk large enough for screw to pass through.

2. Make pushrod as shown.

Note: Gun barrel is slightly less than 3/4 inch in diameter. If rubber disk does not fit in barrel, file or trim it very slightly. It should fit tightly.

3. Drill a hole through the center of one wooden block of such size that the pushrod will fit tightly. Whittle a depression around the hole on one side approximately 1/8 inch (3 mm) and large enough for the grenade to rest in.

4. Place the base of the grenade in the depression in the wooden block. Securely fasten grenade to block by wrapping tape (or wire) around entire grenade and block.

Note: Be sure that the tape (or wire) does not cover hole in block or interfere with the operation of the grenade safety lever.

5. Drill hole through the center of the second wooden block, so that it will just slide over the outside of the gun barrel.

6. Drill a hole in the center of the bottom of the tin can the same size as the hole in the block.

7. Attach can to block as shown.

8. Slide the can and block onto the barrel until muzzle passes can open end. Wrap a small piece of tape around the barrel an inch or two from the end. Tightly wrapped string may be used instead of tape. Force the can and wooden block forward against the tape so that they are securely held in place. Wrap tape around the barrel behind the can.

Caution: Be sure that the can is securely fastened to the gun barrel. If the can should become loose and slip down the barrel after the launcher is assembled, the grenade will explode after the regular delay time.

9. Remove crimp from a 12 gauge shotgun cartridge with pen knife. Open cartridge. Pour shot from shell. Remove wads and plastic liner if present.

10. Empty the propellant onto a piece of paper. Using a knife, divide the propellant in half. Replace half of the propellant into the cartridge case.

11. Replace the 12 gauge cardboard wads into cartridge case.

Note: If wads are not available, stuff tissue paper or cotton into the cartridge case. Pack tightly.

#### How to Use

##### Method I – When Ordinary Grenade is Used

1. Load cartridge in gun.

2. Push end of pushrod without the rubber disk into hole in wooden block fastened to grenade.

3. Slowly push rod into barrel until it rests against the cartridge case and grenade is in can. If the grenade is not in the can, remove rod and cut to proper size. Push rod back into barrel.

4. With can holding safety lever of grenade in place, carefully remove safety pin.

Caution: Be sure that the sides of the can restrain the grenade safety lever. If the safety lever should be released for any reason, grenade will explode after regular grenade delay time.

5. To fire grenade launcher, rest gun in ground at angle determined by range desired. A 45 degree angle should give about 150 meters (160 yards).

##### Method II – When Improvised Pipe Grenade is Used

An improvised pipe grenade (section 2.1) may be launched in a similar manner. No tin can is needed.

1. Fasten the grenade to the block as shown above with the fuse hole at the end opposite the block.

2. Push end of pushrod into hole in wooden block fastened to grenade.

3. Push rod into barrel until it rests against cartridge case.

4. Load cartridge in gun.

5. Follow step 5 of Method I.

6. Using a fuse with at least a 10 second delay, light the fuse before firing.

7. Fire when the fuse burns to 1/2 its original length.

## 4.3 Grenade Launcher (57 mm Cardboard Container)

An improvised method of launching a standard grenade 150 yards (135 meters) or an improvised grenade 90 yards (81 meters) using a discarded cardboard ammunition container.

Materials Required
Heavy cardboard container with inside diameter of 2-1/2 to 3 inches (5-1/2 to 8 cm) and at least 12 inches (30 cm) long (ammunition container is suitable)
Black powder – 8 grams (124 grains) or less
Safety or improvised fuse (section 6.7)
Grenade (Improvised hand grenade, section 2.1, may be used)
Rag, approximately 30 inches x 24 inches (75 cm x 60 cm)
Paper

Caution: 8 grams of black powder yield the maximum ranges. Do not use more than this amount. See Improvised Scale, section 7.8, for measuring.

#### Procedure

##### Method I – If Standard Grenade is Used

1. Discard top of container. Make small hole in bottom.

2. Place black powder in paper. Tie end with string so contents cannot fall out. Place package in container.

3. Insert rag wadding into container. Pack tightly with caution.

4. Measure off a length of fuse that will give the desired delay. Thread this through hole in bottom of container so that it penetrates into the black powder package.

Note: If improvised fuse is used, be sure fuse fits loosely through hole in bottom of container.

5. Hold grenade safety lever and carefully withdraw safety pin from grenade. Insert grenade into container, lever end first.

Caution: If grenade safety lever should be released for any reason, grenade will explode after normal delay time.

6. Bury container about 6 inches (15 cm) in the ground at 30° angle, bringing fuse up alongside container. Pack ground tightly around container.

Caution: The tightly packed dirt helps to hold the tube together during the firing. Do not fire unless at least the bottom half of the container is buried in solidly packed dirt.

##### Method II – If Improvised Pipe Hand Grenade is Used

1. Follow step 1 of above procedure.

2. Measure off a piece of fuse at least as long as the cardboard container. Tape one end of this to the fuse from the blasting cap in the improvised grenade. Be sure ends of fuse are in contact with each other.

3. Place free end of fuse and black powder on piece of paper. Tie ends with string so contents will not fall out.

4. Place package in tube. Insert rag wadding. Pack so it fits snugly. Place pipe hand grenade into tube. Be sure it fits snugly.

5. Insert fuse through hole in end of cardboard container. Be sure it goes into black powder package.

Note: Cardboard container may be used for only one firing.

6. Follow step 6 of Method I.

#### How to Use

Light fuse when ready to fire.

## 4.4 Fire Bottle Launcher

A device using 2 items (shotgun and chemical fire bottle) that can be used to start or place a fire 80 yards (72 meters) from launcher.

Materials Required
Standard 12 gauge or improvised shotgun (section 3.2)
Improvised fire bottle (section 5.1)
Tin can, about 4 inches (10 cm) in diameter and 5-1/2 inches (14 cm) high
Wood, about 3 inches x 3 inches x 2 inches (7-1/2 cm x 7-1/2 cm x 5 cm)
Nail, at least 3 inches (7-1/2 cm) long
Nuts and bolts or nails, at least 2-1/2 inches (6-1/2 cm) long
Rag
Paper
Drill

If Standard Shotgun is Used
Hard wood stick, about the same length as shotgun barrel and about 5/8 inch (1-1/2 cm) in diameter. Stick need not be round.
2 washers (brass, steel, iron, etc.) having outside diameter of 5/8 inch (1-1/2 cm)
One wood screw about 1 inch (2-1/2 cm) long
Rubber disk, 3/4 inch (2 cm) in diameter and 1/4 inch (6 mm) thick. Leather, cardboard, etc. can be used.
12 gauge shotgun ammunition

If Improvised Shotgun is Used
Fuse, safety or improvised fast burning (section 6.7)
Hard wood stick, about the same length as shotgun barrel and 3/4 inch (2 cm) in diameter
Black powder – 9 grams (135 grains). See section 7.8.

#### Procedure

##### Method I – If Improvised Shotgun is Used

1. Drill hole in center of wood block approximately 1 inch (2-1/2 cm) deep. Hole should have approximately the same diameter as the wooden stick.

2. Drill 2 small holes on opposite sides of the wooden block. Hole should be large enough for bolts to pass through.

3. Fasten can to block with nuts and bolts.

Note: Can may also be securely fastened to block by hammering several nails through can and block. Do not drill holes, and be careful not to split wood.

4. Place wooden stick into hole in wooden block. Drill small hole (same diameter as that of 3 inch nail) through wooden block and through wooden stick. Insert nail in hole.

5. Crumple paper and place in bottom of can. Place another piece of paper around fire bottle and insert in can. Use enough paper so that bottle will fit snugly.

6. Place safety fuse and black powder on paper. Tie each end with string.

7. Thread fuse through hole in plug. Place powder package in rear of shotgun. Screw plug finger tight into coupling.

Note: Hole in plug may have to be enlarged for fuse.

8. Insert rag into front of shotgun. Pick rag against powder package with stick. Use caution.

##### Method II – If Standard Shotgun is Used

1. Follow steps 1 and 2, Shotgun Grenade Launcher, section 4.2.

2. Follow procedure of Method I, steps 1–5.

3. Follow steps 9, 10, 11, Shotgun Grenade Launcher, section 4.2, using 1/3 of total propellant instead of 1/2.

4. Load cartridge in gun.

#### How to Use

1. Insert stick and holder containing chemical fire bottle.

Caution: Do not tilt muzzle downward.

2. Hold gun against ground at 45° angle and light fuse.

Note: Steps 1 and 2, How to Use, same for both standard and improvised shotguns.

Caution: Severe burns may result if bottle shatters when fired. If possible, obtain a bottle identical to that being used as the fire bottle. Fill about 2/3 full of water and fire as above. If bottle shatters when fired instead of being launched intact, use a different type of bottle.

## 4.5 Grenade Launchers

A variety of grenade launchers can be fabricated from metal pipes and fittings. Ranges up to 600 meters (660 yards) can be obtained depending on length of tube, charge, number of grenades, and angle of firing.

Materials Required
Metal pipe, threaded on one end and approximately 2-1/2 inches (6-1/4 cm) in diameter and 14 inches to 4 feet (35 cm to 119 cm) long depending on range desired and number of grenades used
End cap to fit pipe
Black powder, 15 to 50 grams, approximately 1-1/4 to 4-1/4 tablespoons (section 1.3)
Safety fuse, fast burning improvised fuse (section 6.7) | or | Improvised electric bulb initiator (section 6.1 – automobile light bulb is needed)
Grenade(s) – 1 to 6
Rag(s) – about 30 inches x 30 inches (75 cm x 75 cm) and 20 inches x 20 inches (55 cm x 55 cm)
Drill
String

Note: Examine pipe carefully to be sure there are no cracks or other flaws.

#### Procedure

##### Method I – If Fuse is Used

1. Drill small hole through center of end cap.

2. Make small knot near one end of fuse. Place black powder and knotted end of fuse in paper and tie with string.

3. Thread fuse through hole in end cap and place package in end cap. Screw end cap onto pipe, being careful that black powder package is not caught between the threads.

4. Roll rag wad so that it is about 6 inches (15 cm) long and has approximately the same diameter as the pipe. Push rolled rag into open-end of pipe until it rests against black powder package.

5. Hold grenade safety lever in place and carefully withdraw safety pin.

Caution: If grenade safety lever is released for any reason, grenade will explode after regular time (4–5 seconds).

6. Holding safety lever in place, carefully push grenade into pipe, lever end first, until it rests against rag wad.

7. The following table lists various types of grenade launchers and their performance characteristics.

Desired Range | Number of Grenades Launched | Black Powder Charge | Pipe Length | Firing Angle
--- | --- | --- | --- | ---
250 m | 1 | 15 grams | 14 inches | 30°
500 m | 1 | 50 grams | 48 inches | 10°
600 m (a) | 1 | 50 grams | 48 inches | 30°
200 m | 6 (b) | 25 grams | 48 inches | 30°

(a)For this range, an additional delay is required. See section 6.11 and section 6.12.
(b)For multiple grenade launcher, load as shown.

Note: Since performance of different black powder varies, fire several test rounds to determine the exact amount of powder necessary to achieve the desired range.

#### How to Use

1. Bury at least 1/2 of the launcher pipe in the ground at desired angle. Open end should face the expected path of the enemy. Muzzle may be covered with cardboard and a thin layer of dirt and/or leaves as camouflage. Be sure cardboard prevents dirt from entering pipe.

Note: The 14 inch launcher may be hand held against the ground instead of being buried.

2. Light fuse when ready to fire.

##### Method II – If Electrical Igniter is Used

Note: Be sure that bulb is in good operating condition.

1. Prepare electric bulb initiator as described in section 6.1.

2. Place electric initiator and black powder charge in paper. Tie ends of paper with string.

3. Follow above procedure, steps 3 to end.

#### How to Use

1. Follow above How to Use, step 1.

2. Connect leads to firing circuit. Close circuit when ready to fire.

## 4.6 60 mm Mortar Projectile Launcher

A device to launch 60 mm mortar rounds using a metal pipe 2-1/2 inches (6 cm) in diameter and 4 feet (120 cm) long as the launching tube.

Materials Required
Mortar, projectile (60 mm) and charge increments
Metal pipe 2-1/2 inches (6 cm) in diameter and 4 feet (120 cm) long, threaded on one end
Threaded end cap to fit pipe
Bolt, 1/8 inch (3 mm) in diameter and at least 1 inch (2-1/2 cm) long
Two (2) nuts to fit bolt
File
Drill

#### Procedure

1. Drill hole 1/8 inch (3 mm) in diameter through center of end cap.

2. Round off end of bolt with file.

3. Place bolt through hole in end cap. Secure in place with nuts as illustrated.

4. Screw end cap onto pipe tightly. Tube is now ready for use.

#### How to Use

1. Bury launching tube in ground at desired angle so that bottom of tube is at least 2 feet (60 cm) under ground. Adjust the number of increments in rear finned end of mortar projectile. See following table for launching angle and number of increments used.

2. When ready to fire, withdraw safety wire from mortar projectile. Drop projectile into launching tube, finned end first.

Caution: Be sure bore riding pin is in place in fuse when mortar projectile is dropped into tube. A live mortar round could explode in the tube if the fit is loose enough to permit the bore riding pin to come out partway.

Caution: The round will fire as soon as the projectile is dropped into tube. Keep all parts of body behind the open end of the tube.

Desired Range (Yards) | Maximum Height Mortar Will Reach (Yards) | Required Angle of Elevation of Tube (Measured from Horizontal Degrees) | Charge – Number of Increments
--- | --- | --- | ---
150 | 25 | 40 | 0
300 | 50 | 40 | 1
700 | 150 | 40 | 2
1000 | 225 | 40 | 3
1500 | 300 | 40 | 4
125 | 75 | 60 | 0
300 | 125 | 60 | 1
550 | 250 | 60 | 2
1000 | 375 | 60 | 3
1440 | 600 | 60 | 4
75 | 100 | 80 | 0
150 | 200 | 80 | 1
300 | 350 | 80 | 2
400 | 600 | 80 | 3
550 | 750 | 80 | 4