Cut a length of time fuse long enough to permit the person detonating the charge to reach a safe distance from the
explosion by walking at a normal pace. Make this cut squarely across the time fuse. A rough, jagged-cut fuse
inserted into the blasting cap can cause a misfire. Insert the time fuse through the plastic priming adapter, if one
is used, with the threaded end toward the end of the time fuse to be capped.
Blasting Cap. The third component is the M7 nonelectric blasting cap. It contains a flame-sensitive
explosive that detonates and causes the main charge to explode. After removing one cap from the cap box,
inspect it by looking into the open end. If any foreign matter is present, remove it as follows:
Hold the cap near the open end between the thumb and middle finger of one hand.
Aim the open end of the cap at the palm of the other hand.
Gently bump the wrist of the hand holding the cap against the wrist of the other hand.
If the foreign matter does not come out, obtain another cap, and dispose of the first one on the demolition
Inspect the second cap.
Do not blow into the open end of the cap to clear foreign material.
Hold the time fuse upright with the square-cut end pointing up. Slip the blasting cap gently down over it so that
the flash charge is in contact with the time fuse. Never force the time fuse into the blasting cap by twisting or any
other method than that described. This could cause it to detonate in your hand. If the end of the time fuse is too
large to enter the blasting cap freely, roll the time fuse between your thumb and fingers until it fits.
After the blasting cap has been seated, grasp the time fuse between the thumb and third finger of one hand so that
your fingers are touching the open end of the cap. Place your forefinger over the closed end of the cap to hold it
firmly against the end of the time fuse. Apply slight pressure on the closed end of the cap with your forefinger.
Rest the crimpers on the top of the thumb and ring finger of your other hand. Place your second finger on top of
the crimpers to secure them. Accurate crimping can be performed even in darkness, because a finger can be used
to locate the open end of the blasting cap.
Crimp the blasting cap at a point one-eighth to one-quarter inch from the open end. A crimp too close to the
explosive in the blasting cap may cause detonation. Point the cap out and away from your body during crimping.
Note that the outer jaws of the crimper are for crimping the blasting cap. The inner jaws are for cutting time fuse
or detonating cord.
Occasional nonelectric misfires occur. The main reason for dual priming is the prevention of misfires.
Investigation and correction should be undertaken only by the individuals who placed the charge. Investigate the
misfire at least 30 minutes after the expected time of the detonation. For example, 30 minutes of safety time plus
10 minutes of expected burning time equals 40 minutes of waiting time. This allows for delays caused by
defective powder trains in time fuses. Under combat conditions, however, immediate investigation may be
necessary. If the misfired charge is not tamped, do not move or disturb it. Lay and fire a primed one-pound
charge beside the misfired charge.
The Electric Firing System
This system is preferred when time allows its use. It is preferred because it provides total control of when the
shot will be fired. The major drawback to the electric firing system is the amount of equipment it requires. This