Correct me if I am wrong, but C4 can only be detonated by an electrical current right? I've read about U.S. soldiers in Vietnam using C4 to cook with. Is current C4 still this stable?
C4 is very stable. the only refinements that I know of was in the late 60's where they removed a chemical from the composition. Soldiers were chewing it and the chemical would give them a great high, however if the entire compound were swallowed it could be fatal.
C4, like any other hi-explosive, must have an explosive train to detonate it. It needs a small detonation proportionate to the size of the charge to make it go boom. Electrical current alone will not do anything to the C4, however the current (most popular) way of detonating C4 charges are using a eletrical blasting CAP. Maybe this is what you are refering too? The statement about US soldiers using it to cook with is likely true. However, when C4 is lit, it is VERY unstable. Stepping on a small lit portion would very likely cause a detonation. But as soon as the fire is out, the C4 is once again stable.
To go a little further and in general, all explosives are classified in two categories-- Lo-explosives, Hi-explosives. What determines what category is the burn rate of the composition. If I recall correctly, the line is drawn at 14,000 FPS. Anything under that is considered lo, such as gunpowder, black powder (not confined). ANything over 14K per sec is considered Hi. Examples are Comp B, RDX, PETN, C4 (very fast burning, unsuitable for encased munitions), tritonal, minol, TNT, Black powder (when sufficiently confined).
BTW, TNT is not safe to burn, it will cook off and detonate. Most likely it was C4
just the tip of the iceberg on this subject. Sorry I gave ya more than you wanted maybe.