30 CFR 57.6304 - Primer protection.
(a) Tamping shall not be done directly on a primer.
(b) Rigid cartridges of explosives or blasting agents that are 4 inches (100 millimeters) in diameter or larger shall not be dropped on the primer except where the blasthole contains sufficient depth of water to protect the primer from impact. Slit packages of prill, water gel, or emulsions are not considered rigid cartridges and may be drop loaded.
Title 30 published on 2015-07-01
The following are ALL rules, proposed rules, and notices (chronologically) published in the Federal Register relating to 30 CFR Part 57 after this date.