CARTRIDGE MANUFACTURE A TREATISE COVERING THE MANUFACTURE OF RIFLE CARTRIDGE CASES. ::SULLETS, POWDERS, PRIMERS AND CARTRIDGE CLIPS, AND THE DESIGN- ING AND MAKING OF THE TOOLS USED IN CONNEC- TION WITH THE PRODUCTION OF CARTRIDGE CASES AND BULLETS, TOGETHER WITH A DESCRIPTION OF THE PRINCIPAL QPERATIONS IN THE MANU- FACTURE OF COMBINATION PAP ER AND BRASS SHOT SHELLS By DOUGLAS T. ~AMILTON AssoclATB EDITOR OP MACHINERY AtrrHOR OP "ADVANCED GRINDING PltACTJCB." ''AUTOMATIC ScREW MACHINB PRAcncs.'' "SHRAPNEL SHELL MANUPACTURB" "MACHINE FORGING," ETC. FIRST EDITION NEW YORK THE INDUSTRIAL PRESS 1916 WWW.RIFLEMAN.ORG.UKCHAPTER Ill MANUFACTURE OF 0.22-CALIBER RIFLE RIM-FIRE CARTRIDGES IN the manufacture of rim-fire cartridges, of which the 0.22 long-regular type of cartridge· may serve as a suitable example, the important operations are as follows: Blank- ing, cupping, drawing, annealing, washing, drying, trim- ming, heading, priming, loading, and inspecting. This chap- ter describes the practice of the Dominion Cartridge Co. in making cartridges of this size and type. A description of the manufacture of the lead bullets used in this size of cartridge is also included. Cupping and Annealing. -The first operation in the manufacture of rim-fire (RF) cartridges is to produce a cup of the required size by means of a combination blank- ing and cupping punch and die. The cartridges are usually blanked and cupped at a rate of from four to six for each stroke of the press. The cup is made from a blank sheet of copper of the required width and thickness. Before any drawing operation can be performed on the cups, they must be annealed to make them ductile. The cups are placed in a cylindrical cast-iron drum, shown in Fig. 1, which has holes, smaller in diameter than the smallest cups annealed in it, drilled around its periphery. These holes. permit the heat to permeate, thus annealing the cups rapidly. The cylin- drical drum is provided with a slide or ·door, which is forced in when the cups are inserted. The drum is then rolled into the furnace, where it is rotated by means of a chain and sprocket, driven by an overhead shaft. The door A, which is shown in the upper position in Fig. 1, is then brought down. Before the cups are inserted, the drum must be he·ated to a cherry red. Then the cups are put in and allowed to remain for a period of from thirty to forty min- utes. ·After the cups have remained in the drum the speci- fied time, the front door is raised and the drum rolled out. A truck with a pan located on it is then rolled in front of 22 WWW.RIFLEMAN.ORG.UKthe annealer, the sllde taken out, and the cups dumped into this pan, which is filled with lukewarm water. Washing the Cups.- In the annealing process, a scale is formed on the cups, which would be detrimental in draw- ing; therefore, before any drawing operations can be car- ried out, they must be washed. To accomplish this, the cups are dumped into revolving tubs, as shown in Fig. 2. These tubs are driven by a shaft located beneath them. through bevel gears. A clutch is also provided, so that any one of the tubs may be stopped, if desired, independently of the others. By rotating these tubs, the cups are made to rub against one another, thus helping to remove the Fig. 1. Cylindrical Drum In which the Cupa are Annealed scale. The rotation of the cups and the pouring of water on them is not sufficient to remove the scale, so they are immersed in a solution composed of sulphuric acid and water, mixed together in the following proportions: Water, 48 pints; sulphuric acid, 1/4 pint. This solution is used for the first washing and removes the scale. When the cups look quite clean, a plug is removed and the acid solution washed off. Then the plug is inserted and another solution composed of pearlash soda, soft soap, and water is mixed together in the following proportions: Water, 48 pints; soft soap, 1 pint; pearlash soda, 14 pint. The cups are WWW.RIFLEMAN.ORG.UKrotated in this solution for about twenty ~inutes, after which they are rinsed with warm water. A sieve is located over the hole for the plug so that the cups cannot fall out. When the cups have been thoroughly rinsed and the water drained off, they are put in sieves, which, in turn, are placed in a cupboard, where they are held in racks. Steam pipes are located beneath these racks, so that the cups are quickly dried. Fig. 2. Tuba used In Wash· Fig. 3. Vertical Header with lng the Cups after Annealing Automatic Feed Drawing Operations.- When dry, the cups are trans- ferred to the drawing department. Here they are put in a pan, from which the operator removes them by means of a vulcanite plate. This plate has a series of holes drilled through it, which are bell-mouthed on the top, and are slightly larger in diameter than the cups. A thin sheet- steel plate, bent up on two sides to fit the vulcanite plate, is slipped under it when shaking in the cups. When the cups are shaken into the plate, the operator places it on the table WWW.RIFLEMAN.ORG.UKA of the doul:ile-headed friction-dial drawing press shown in Fig. 4, after which the sheet-steel plate is removed, and the vulcanite plate lifted up, leaving the cups standing on the table A. The operator then shoves the cups from the table onto the friction dial B, which carries them to the dies. These friction dials are driven through bevel gears by a round belt, which is connected through three grooved pulleys to the main driving pulley. The cups pass between the guard C and spring D, the latter being vibrated by the action of the revolving dial, which keeps the cups in con- stant motion, thus arranging them in single file. The guard C and the spring D approach each other as they near the Fig. 4, Double.headed Frlctlon·dlal Drawing Preaa uaed for . the Varloua Drawing Operation• dies to within a distance equal to the diameter of the cups. The cups are carried from the dial-to the dies by a finger E connected to the bellcrank F, which, in turn, is operated by the cam G on the end of a vertical shaft, driven from the crankshaft through bevel gears. The action of drawing the cups through the dies is clearly shown in Fig. 5. The cup is carried out by the finger and placed over the die i. The punch h then descends in it, as shown at A, forcing it down into the die, as shown at B. In the latter position, the case is given a mushroom shape, and is then forced through the die, as at C, reducing it in WWW.RIFLEMAN.ORG.UKdiameter, increasing its length and decreasing the thickness of its walls. As the cup is forced through the die, it ex- pands slightly away from the punch, and on the upward stroke of the press it catches on the bottom of the die, and is stripped from the punch, dropping into a box placed under the machine. Only one die is shown in the illustra- A B Fig. 15. Diagram ahowlng the Action of Drawing the Cupa tion, but in actual practice two drawing dies are used, one on top of the other. The lower die is not bell-mouthed, but is slightly tapered. In the drawing operations it is neces- sary to lubricate the cups, so that they will not stick to the die or punch, and for this purpose a lubricant composed of SQft soap and water is used. This is placed on the cases while they are located on the dial, by the operator, who Fig. 6. Jlluatratlon ahowlng the Tranaltlon from the Cup to the Flnlahed Cartridge spreads the lubricant over them by means of a small cup fastened to a handle. The punch for the drawing opera- tions is made slightly tapered, being smaller at the lower end, as shown in Fig. 5. This is necessary, as the explosive material is placed near the head of the case, thus requiring the walls to be thicker at this point than near the mouth. WWW.RIFLEMAN.ORG.UKAfter the first drawing operation, the cups are taken to the annealer, again annealed, washed, and dried, in the manner previously described. They are then brought back to the drawing presses for the second drawing operation. After this, they again pass through the operations of an- nealing, washing, and drying, after which they are taken to the drawing presses for the third or finish-drawing operation, that is performed as previously described. The transition of the cup A to the case is clearly shown in Fig. 6. Here the three d r a w i n g operations are shown at B, C, and D, respectively. After the three drawing op- erations, the cases are a g a i n washed a n d dried (not annealed) , when they are taken to the trimmers, one of which is shown in Fig. 7. As shown in Fig. 6, the mouth of the cup is not left per- fectly straight after the drawing opera- tions, but has ragged edges. Cracks also SOmetimes develop in Fig. 7. Automatlo Trimming Machine for Trimming the Caaea to Length the mouth of the case, which make it necessary to trim off a certain amount, to obtain a perfect case. Trimming the Case to Length.- In the trimming oper- ation, the cases are dumped into the hopper A, shown at the top of the machine, Fig. 7, and pass from the latter into the revolving drum B, to which segments, having pins C driven into them, are fastened. These pins, which are smaller in diameter than the inside of the case, are pointed WWW.RIFLEMAN.ORG.UKand set at an angle. As the segments carrying the pins rotate, the cases are agitated and drop onto the pins. The pins now carry the cases to the top of the hopper, and as they approach the perpendl.cular position, the cases drop off, and fall into the chute D, which is connected to the machine by a close-wound spring E, and tube F. A better idea of the operation of this trimming machine can be obtained by referring to Fig. 8. Here the cases are shown dropping down the chute. They are held by a finger a, which presses Machtneru.N. y,, Fig. 8. Diagram ahowlng the Action of the Automatic Trimming Machine against them, allowing only one case to drop out at a time. In the position at A, one case has dropped into the segment b, and the next case is being held by the finger a. This finger is released by a cam, located at the rear of the ma- chine. Attached to the face of the segment b is a sheet- steel plate c, the function of which is to prevent the cases from dropping out. This sheet-steel plate is held by a dowel-pin and two screws as shown. Spiral springs are WWW.RIFLEMAN.ORG.UKlocated under the heads of these screws, thus giving the plate the desired tension on the case. After the cases are located in the pocket, the segment. is revolved in the direction of the arrow, carrying the case into the horizontal position as shown at B. The punch d now advances and carries the case out of the pocket into the chuck e. The chuck begins to close before the punch reaches the end of its travel, so that the punch can force the case in to the correct depth. The punch d is held in a slide, actuated by an eccentric crankshaft which connects the punch-slide G to the disk H (Fig. 7) ; the latter is driven from the rear shaft through bevel gears. When the case is Fig. 9. Horizontal Header with Semi-automatic Feed for Forming the Head on the Caae located in the chuck, the latter is closed by means of a cam located on the rear shaft of the machine, which operates through a lever forcing the beveled sleeve I forward. This beveled sleeve I raises the lever to which the roll h is attached, and doses the chuck by means of the screw i pressing on the outer sleeve j. The punch d then retreats and the trimming tool k advances, trimming the case to length. The inner face of this tool is slightly offset as shown, so that it will take a light shaving cut after cutting the end off. This makes a good finish and does not throw any burrs into the case. The segment b now rotates back WWW.RIFLEMAN.ORG.UKNext >