Pyrotechnic formulations such as the following can be used. Ignition charge 334 weighs approximately 100 mg and has a composition by weight of 65 %±5
% zirconium, MIL-Z-399, type 2, class 2; 25 %±3% iron oxide, TT-P-375, type 1 or 2; 10 %±2 % diatomaceous earth having the following
characteristics: 0.4 % loss of weight on ignition, 90 % minimum silica, and 99 % minimum granulation passing through a 325 mesh; and 0.5 % maximum
binder. Delay charge 332 weighs approximately 1200 mg and has a composition by weight of 49 % tungsten MIL-T-48140, amend. I; 5% potassium
perchlorate, MIL-P-217, grade A, class 4; 41 % barium chromate, MIL-B-550, grade A; and 5 % diatomaceous earth having the following characteristics:
0.4 % loss of weight on ignition, 90 % minimum silica, and 99 % minimum granulation passing through a 325 mesh; and 0.5 % maximum binder. Penetration
charge 330 weighs approximately 100 mg and has a composition by weight of 75 %±5 % iron oxide, TT-P-375, type 1 or 2; 25 %±5 % magnesium, MIL-M-382,
type 1, grade A, granulation 12; 0.5 % maximum binder. The binder can be omitted from ignition charge 334 and penetration charge 330, and the
proportions of ingredients in delay charge 332 can be varied in a known manner to obtain the desired burning rate without jeopardizing the safety
features herein described.
The charges are assembled in the following manner. Penetration charge 330 is inserted into bottom 306 of delay case 302 with a load of 20,000 to
40,000 lb./sq.in. for a pre-established dwell period of 3.0 sec. ±0.5 sec. Three increments of delay charge 332 are then pressed into delay case 302
directly on top of penetration charge 330 with a load of approximately 40,000 lb./sq.in. for a pre-established dwell period of 3.0 sec. ±0.5 sec.
Finally, ignition charge 334 is pressed into delay case 302 directly on top of delay charge 332 with a load of approximately 40,000 lb./sq.in. for a
pre-established dwell period of 3.0 sec. ±0.5 sec. |
