The vents should be examined with the vent-gauges and searchers, to see that they are clear from any substance which may obstruct the use of priming-wires and primers.
53. The carriages are also to be carefully examined, the trunnion-holes and arms of the axletrees cleaned, and saturated with boiled linseed oil, the cracks filled with putty, and rubbed smooth, and the trunnion-holes black-leaded. The iron work should be freed from rust, all screws be made to work easily, and be well cleaned and coated with proper composition.
54. The Ordnance Officers will see that the sights are properly fitted and marked for their proper guns. The greatest care should be taken that they are properly adjusted, as the efficiency of the ship depends on it, and it is difficult to detect or remedy any error after they are placed on board; that the beds and quoins are fitted and adjusted, and the quoins graduated to degrees or distances to correspond with those marked on the sight-bars. Porter's quoin is adopted for all carriages requiring quoins.
55. New guns are to have locks fitted to them before being put on board ship. Those having two lugs will have the one on the right fitted; the other is to be left solid.
56. When the guns are to be shipped for transportation merely, the same precautions are to be taken to guard them from injury as on shore, with the addition of a wad dipped into the composition which covers the bore, thrust into the muzzle, and connected with the tompion by a lanyard.
In the transportation of guns by rail—unboxed—the vents are to be plugged with soft wood, puttied over, and turned vent downwards on the trucks. All bronze howitzers transported by rail shall be boxed.
57. At the termination of a cruise the guns composing the battery of every vessel-of-war of the United States, shall be carefully examined by the Ordnance Officer of the Yard, and such others as may be directed, with the view to discover and report any injuries which they may have sustained in service, or any defects which may not have been developed in the original proof. In this examination the attention of the Inspecting Officers is to be directed to the following points, viz.:
Enlargement of the interior or exterior orifice of the vent.
Indentations or hollows produced by the shot balloting against the surface of the bore, or by the action of the gases.
Cuts or scratches in the bore, produced by fragments of broken or the roughness of imperfect shot.