Nothing in this article shall prevent the manufacture, purchase, sale, transportation and use of explosives or signaling flares used in the course of ordinary business or industry, or shells or cartridges used as ammunition in firearms. This article shall not apply to the sale, use or possession of explosive caps designed to be fired in toy cap pistols, provided, that the explosive mixture of explosive caps shall not exceed twenty-five hundredths of a grain for each cap.
(`86 Code, § 8-62)