Ammunition for Field Service is composed of [solid shot], [shells], [spherical case-shot], and [canister-shot] (see headings). In mountain service solid shot are omitted. A stand of ammunition is composed of the projectile, sabot, straps, cartridge-bag, cylinder, and cap. The projectile is secured by two tin straps, fastened at the ends with tacks driven into the sabot. The straps cross each other at right angles; for solid shot, one strap passing through a slit in the other; for hollow projectiles, both straps are fastened to a tin ring which surrounds the fuze-hole. A round of canister for the field service consists of a tin cylinder filled with cast-iron shot, which slips over the end of the sabot, to which it is secured with small nails. The materials of which cartridge-bags are made are flannel, wildbore, or serge; the fabric should be soft and closely woven, to prevent the powder sifting out. Fabrics of cotton and flax are not used, because the powder sifts through them, and they are more apt to leave fire in the gun than woolen stuffs. A cartridge-bag for the field service is made of two pieces,—a rectangular piece for the sides, and a circular piece for the bottom. The charge is determined by measurement. The cylinder and cap are made of stout paper. The cylinder is used to give stiffness to the cartridge at the junction of the sabot and bag; the cap covers the exposed portion of the bag, is drawn off before loading, and placed over the projectile, or thrown away. The cartridge-bag is attached to the projectile by tying it around the grooves of the sabot with twine.
Fixed Ammunition.—Ammunition thus prepared is called fixed ammunition. It is used in the field and mountain service for smooth-bore guns and howitzers. For rifled guns the bag and projectile are carried separately. The term strapped ammunition is applied when the projectile is attached to a sabot without grooves; and to give a proper form to the cartridge-bag, the mouth is closed with a cartridge-block, which resembles a sabot; hence the name strapped ammunition. This kind of cartridge is nearly obsolete.
Packing, etc.—As soon as ammunition is finished it should be gauged, to see that it is of the proper caliber; it is afterwards packed in boxes containing 10 rounds each.
Siege and Sea-coast Ammunition.—On account of the great weight of siege and sea-coast ammunition, the cartridge-bag and projectile are carried separately. The cartridge-bags for large charges of powder are made of two pieces of woolen stuff, or of a paper tube with a woolen cloth bottom. The former are preferred for rapid firing. For sea-coast howitzers the bag should fill the chamber; if the piece be fired with a reduced charge, a cartridge-block should be inserted into the bag to give it proper size. For mortars the bag is only used to carry the powder, and when the piece is loaded, the powder is poured into the chamber; bags of any suitable size will answer for this service. For hot-shot cartridges bags are made double, by putting one bag within another. Care should be taken to see that the bags are free from holes. For ricochet firing, or other occasions when very small charges are required, a cartridge-bag of inferior caliber may be used. In the siege and sea-coast services, solid shot are transported and loaded loosely, but hollow projectiles are strapped to sabots, to prevent the fuze from coming in contact with the powder of the charge. The sabots are made from thick plank, and the straps are fastened as in the field service.
Ordnance, Carriages for. The carriages for cannon may be classified from their use into [field], [mountain], [prairie], and [sea-coast carriages], and [mortar-beds]. (See particular headings.) They may be further divided into those required for the immediate service and transportation of cannon, as gun-carriages and mortar-beds, and those employed for the transportation of ammunition, implements and materials for repairs, as caissons, mortar-wagons, forges, and battery-wagons. The field-, mountain-, prairie-, and siege-carriages being required for the transportation of their pieces are similar in their construction; those for sea-coast purposes differ materially from the others.
Nomenclature of Artillery Carriage.—The principal parts of the field-carriage and of all artillery carriages, other than the sea-coast, are: stock, of squared wood in two pieces, which serves to connect the gun-carriage with the limber, and to direct the piece; it includes the head, to which the sponge-bucket ring is attached; groove, trail, or curved part of the stock, which rest on the ground when the piece is unlimbered; rounding of the trail, trail-plate, a piece of iron fastened to the end of the trail and terminated by a very strong ring, called the lunette, which receives the pintle-hook by which the limber is attached; pointing-rings, large and small, which receive the hand-spike; trail-handles, on each side of the stock for the purpose of raising it; prolonge-hooks, on which the prolonge is coiled; wheel-guard plates, lock-chain, used to keep the wheel from turning; it is on the side of the carriage, and has an eye-plate and bolt; sponge and rammer stop, sponge-chain and hasp, ear-plate for sponge-chain and hasp; ear-plate to support worm; key-chain and key; elevating-screw; the latter has a handle with four prongs; elevating-screw box, elevating-screw bed, rondelles, which connect cheeks and stock; cheeks, two pieces of wood between which the gun rests; washer-hooks for handspike, washer-hook for lock-chain, under-strap, right sponge-hook, sponge and worm-hook, handspike-rings, trunnion-plates, into the beds or depressions of which the trunnions fit; cap-squares, cap-square chain, key-chain and key. Axle, including axle-body, of wood; axle-tree, of iron, axle-arm, the rounded extremities of the axle-tree on which the wheels revolve; linch-pin, linch-pin washer and hook. Wheels; each includes nave, nave-bands, nave-box, spokes, felloes, tire. In the new model for field service, cannoneers’ seats are on the axle between the cheeks and wheels; each consists of an iron chair supported on a rectangular bar inserted in a vertical iron socket, and resting on a strong steel spring; the socket is supported by two brass braces fastened to the axle by axle-straps; to an iron cross-piece at the top of the socket are attached two iron braces, which help to support the iron foot-rest attached to the brass braces. The chair has arms and faces to the trail. This refers to the carriage proper, considered only in relation to the fire of the piece, or as a two-wheeled carriage. To suit it to the easy and rapid transportation of its load it must be converted into a four-wheeled carriage, which is done by attaching it to another two-wheeled carriage called a limber.
The limber consists of a similar axle-body, axle, and two wheels, and on these rests a frame-work, to receive the tongue. On top of the whole is an ammunition-box, the top of which forms a seat for three cannoneers. In rear of the axle-tree is a pintle-hook to receive the lunette of the trail. Connected with the frame-work in front is a fixed splinter-bar with four hooks, to which are attached the traces of the wheel horses. At the extremity of the tongue are placed two pole-chains, by which the tongue or pole is held up, and a pole-yoke with two movable branches, to prevent, as much as possible, the pole from oscillating and striking the horses. The principal parts of a field-limber are: pole, including pole-pad; pole-straps, by which the pole is guided when the team is hitched; pole-strap iron, pole-yoke, muff and collar, pole-yoke branches, to which are attached sliding-rings; splinter-bar, to which the horses are hitched by four trace-hooks; end-bands, middle-bands, pole-prop, including socket, ferrule, and chain; hounds, pieces of wood upon which the chests rest, connecting the axle-body with the splinter-bar; forks, pieces of wood between the hounds, forming an opening in which the pole is placed; fork-strap, foot-boards, foot-board brackets, chest, chest-handles, cover, of wood; cover-plate, of copper; turnbuckle, hasp, back-stay, front-stay, stay-pins, stay-pin keys, under strap, pintle-hook, on rear part of axle-tree, which attaches the limber to the carriage; pintle-hook key, axle, wheels. The field-carriages employed in the U. S. service are three, one for the 3-inch rifle carriage (which, with slight modifications, is adapted to the 1-inch mitrailleur), one for the 12-pounder, and one for the 1⁄2-inch and .45-inch mitrailleur. The corresponding parts of these carriages differ only in their dimensions. All limbers are similar.
Mountain-Carriage.—The mountain-carriage differs in construction from the field-carriage inasmuch as the stocks and cheeks are formed of the same piece by hollowing out the head of the stock, the wheels are smaller and the axle-tree is made of wood, the arms being protected from wear by skeans. It is arranged for draught by attaching a pair of shafts to the trail. The pack-saddle and its harness are constructed to carry severally the howitzer and shafts, the carriage, or two ammunition-chests; or it enables an animal to draw the carriage with the howitzer mounted upon it.
Prairie-Carriage.—The prairie-carriage is designed to carry the mountain howitzer, and is similar to the mountain-carriage in form; but being exclusively for draught, the axle-tree is of iron, and the wheels are made higher and the distance between them greater than in the mountain-carriage. It has a limber and is drawn by two horses abreast, as in field-carriages. The ammunition is packed in mountain ammunition-chests, two of which are carried on the limber.
Siege-Carriages.—There are three different kinds of siege-carriages used in the U. S. service, one for the 41⁄2-inch rifle, another on which the 30-pounder Parrott is mounted, and a third for the 8-inch howitzer, being the old 12-pounder, 18-pounder, and 24-pounder siege-carriages modified; these are all constructed in the same manner, and differ only in their dimensions. Siege-carriages are similar to the field-carriage in construction (see [Field-carriage]), the principal difference being in the manner in which they are joined to the limbers. Projecting upwards from the limber and in rear of the axle-tree is placed a pintle, which enters a hole made in the trail from the under side, and a lashing chain and hook keep the two parts together when once in position; the weight of the stock bearing on the rear of the limber relieves the horses of the weight of the pole, which is long and heavy. On the upper surface of the cheeks near the rear ends are placed two projecting bolts, which with the curve of the cheeks form resting-places for the trunnions, when the piece is in position for transportation. They are called traveling trunnion-beds. When the piece is in this position the breech rests upon the bolster, which is a curved block of wood bolted to the upper side of the stock.