With explosives, you must reach the speed of detonation to have an explosion. Explosives are rated in feet per second, that is, a mathematically arrived at figure where you could lay out ten miles of the stuff, and time it from one end to the other. Black powder is slower, hence, you have seen the trail of gunpowder lit by the bank robbers and all snaking its way along. Something like 500 fps. That is low order. High order is in the 24,000 fps and up range.
Many high explosives will burn and not explode. C4 plastic explosive was commonly burned in small food stoves in Viet Nam.
A story is told in "Yankee Autumn in Acadiana", an account of the Civil War movement of the North fighting the South as it progressed through southern Louisiana. A particularly loony soldier would commonly use an unexploded "Parrott" shell as a cook surface by building a fire next to it. These were
16" in diameter. He would turn it flat side up. Other soldiers would stay away from his camp. He said it would not ignite. He was wrong, and one night, it did with him cooking dinner. He was never seen again.Steve