bursting charge

from The Century Dictionary.

• noun In mining, a small charge of fine powder, placed in contact with a charge of coarse powder to insure the ignition of the latter.
• noun 2. In ordnance, the charge of powder required for bursting a shell or case-shot.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a quantity of explosive to be set off at one time