80. The greatest care is to be taken to remove every particle of sand or fragment of iron from the interior when they are about to be loaded for service. And the Inspectors of Ordnance at foundries or Navy Yards will satisfy themselves that this has been done before accepting or preparing them for service.
81. The shell is next struck with a hammer, to judge by the ring or sound whether it is free from cracks; and the exterior and interior diameters of the fuze-hole (which should be accurately reamed) are to be verified, and the soundness of the metal about the inside of the fuze-hole ascertained. To determine the thickness of the metal, three points, at least, on the great circle at right angles to the axis of the fuze-hole are to be measured; also one at the fuze-hole and one at the bottom. No shell shall be received which deviates more than one-tenth of an inch from the proper thickness in any part.
82. The shell is next placed in a tub of water, which should be deep enough to completely cover the shell. Air is then forced by the bellows into the shell. If there are any holes in it, air-bubbles will rise on the surface of the water, and the shell shall be rejected.
83. This occasionally occurs from the escape of air from porous spots which do not extend to the interior of the shells. In this case the action of the bellows produces no increase of bubbles, which cease rising as soon as the spots or cavities are filled with water. Porous spots are also detected by their absorbing water and drying slowly when exposed to the air, and shall likewise cause the rejection of the shell.
84. The Inspecting Officers will stamp the shell at one inch from the fuze-hole with their initials, also those of the foundry at which they are cast.
The Inspector or one of his assistants must be present when shot or shell are inspected; and the stamps and marks are always to be retained in the possession of the Inspector.
85. Rejected shells are to be mutilated by chipping a piece out at the fuze-hole.
86. If, upon the inspection of shot or shells, any of them should be found not to conform strictly to these instructions or to the requirements of the contract under which they are offered for reception, the Inspecting Officer is not to receive them; but if, in his opinion, the defects, taken in connection with the general character of the articles, will not impair their efficacy or render them unsafe or hazardous, he may refer to the Chief of the Bureau of Ordnance for his decision, forwarding to him minute and full information on the subject.
87. Shot and shells shall be delivered for inspection at the places specified in the contract, at the expense of the contractor; and those which are rejected shall be immediately removed, also at his expense.