Section 695(18)(iii) in Police Regulations, Bengal , 1943
(iii)Two sealed boxes each containing 180 rounds of ball ammunition (which will be changed once a year) shall be kept at each treasury guard room and one such box containing 180 rounds at each sub-treasury guard room for emergency. The sealed box or boxes will be kept in a strong wooden box which will be attached by a chain to the arms rack and well raised off the ground. One key shall be kept by the guard commander and a duplicate by the Court officer.