18. MINE, ANTIPERSONNEL, M3.

a. General. The MINE, antipersonnel, M3, is a fragmentation type of land mine intended primarily for use against personnel. The complete round consists of the mine, a hollow cast-iron block containing TNT, and FUZE, mine, antipersonnel, M3 or FUZE, mine, com-bination M7. It has an effective radius against personnel of 10 yards when fired at the surface of the ground. The effective radius is slightly increased when the mine is used serveral feet above ground level, and is decreased when the mine is buried in the ground. Fragments of the mine may be thrown more than 100 yards and suitable protection should be provided for friendly personnel within this radius.

b. Description.

(1) The MINE, antipersonnel, M3, is shown with principal dimensions in figure 13. The cast-iron casing is filled with a 0.90-pound charge of flaked TNT. In two opposite sides and one end, there are holes below which are cap wells. Any one of these holes may be used. As shipped, the holes are closed with plastic plugs. In the end opposite the well is a filling hole which is closed with a metal disk.

Figure 13 - MINE, Antipersonnel, M3, Complete

(2) FUZE, mine, antipersonnel, M3 (fig. 14), consists of a special blasting cap (U.S. Army blasting cap, type A) crimped to the Combination Firing Device M1 (par. 24) for use with this mine. The firing device contains a spring-loaded firing pin and a primer. It may be fired by means of a cord or wire connected to the release pin ring, or by pressure applied to the pressure cap. A pressure of 20 to 40 pounds on the pressure cap, or a tension of 3 to 6 pounds on the release pin, will release the firing pin and detonate the primer. Wire is furnished for connecting to the pull ring for making tripping devices. A safety pin located in a hole in the firing pin, and a locking screw bearing on a groove in the firing pin, protect the firing device from accidental functioning during shipping and handling. The firing device is issued unassembled to the mine.

(3) FUZE, mine combination, M7 consists of a firing mechanism with a three-pronged head and a special blasting cap (par. 24.1). A pull of 6 to 10 pounds on the pull ring, or a load of 10 to 20 pounds on all three prongs or of 10 to 30 pounds on one prong will activate this fuze.

Figure 14 - FUZE, Mine, Antipersonnel, M3

c. Operation. To assemble the mine, it is only necessary to remove the closing plug from the desired fuze hole and to screw in the firing device firmly. Be sure that the well is clear of foreign material and that the detonator enters freely.

(1) TO PLANT OR PREPARE FOR ACTION WITH THE M3 FUZE (par. 24 c).

(a) Remove the closing plug. Use the wrench packed with the mines.

(b) Assemble the fuze to the mine.

(c) Attach a trip wire to the release pin ring, or install a pressure trip in the pressure cap.

(d) Check to see that the trip wire is not too tight, or that there is not too much weight on the pressure cap.

(e) remove the locking screw and safety pin. If the safety pin tends to bind, the fuze is unsafe and should not be used.

(f) Special Safety Precaution. This device may fire if the relase pin is rotated after the locking screw is loosened or removed, and the safety pin is removed. Do not adjust the position of the release pin unless the safety pin and locking screw are securely in place.

(2) TO PLANT OR PREPARE FOR ACTION WITH THE M7 FUZE. After removing the closing plug from the mine, install the fuze as directed in paragraph 17c (2).

(3) TO PICK UP OR RECOVER.

(a) Replace the safety pin and screw the locking screw in place.

(b) Cut the trip wire or remove the pressure tripping device from the pressure trip.

(c) Take up the mine.

(d) Remove the fuze from the mine and replace the closing plug.

(e) Repack the components in their original packing. The fiber case in which the fuze is packed should be resealed.

Figure 14.1 - FUZES for mine, antipersonnel, M3

d. Precautions.

(1) No attempt will be made to disassemble the mine or components, except to remove or replace the fuze hole closing plug and assemble or remove the fuze.

(2) Do not remove the locking screw or safety pin from the fuze until the mine is placed and the installation is checked to see that there is not too much tension on the pull ring, or too much pressure on the pressure cap.

(3) Protect the fuze from shock, heat, and friction.

(4) When the mines are being planted, place the fuze hole plug, locking screw, and the safety pin in a position where they may be readily found if necessary to pick up and re-cover the mines.

(5) Exposure to mositure will not affect the operation of the mine. However, the mine is not waterproof, and should not be planted in position where it will be immersed in water for more than a few days.

e. Marking and Packing.

(1) MARKING. The mine body and the fuze are painted olive-drab with markings in black. On one side are marked the type and model of the mine, metal parts manufacturer's lot number, and date of manufacture. The opposite side is marked with the type and model, loader's lot number, and date of loading. The closing disk is painted yellow.

(2) PACKING. Six mines are packed in a wooden packing case, which also contains six fuzes. The fuzes are packed in sealed cylindrical fiber containers which, in turn, are packed in compartments in one end of the packing box. Packed in the box is a small wrench which fits the square holes in the plastic plugs in the mine and is used for un-screwing them prior to assembling the fuzes. Six spools of wire for making tripping devi-ces are also packed in the box. Each spool has four 26-foot lengths of wire. The boxes are marked "OLIVE DRAB" or "SAND COLOR" to indicate the color of the wire packed therein (par. 8).