inch. If no such spring stock is available, it will be necessary to straighten out an existing spring and rewind it in the proper shape.
A mandrel is made by grinding or filing a radius on each edge of a rectangular steel strap cut to the dimensions shown for each caliber. The springs are wound around these mandrels.
Drill a hole just big enough for the spring wire close to one end of the mandrel. Drill another hole that size close to one end of a piece of strap iron about the size of a ten-inch file. Slip one end of the spring wire stock through the hole in the strap iron and the other end into the hole in the mandrel. Then wind the wire around the mandrel, using the strap iron to keep enough tension on the wire to wind the spring strongly and evenly. When completed, a serviceable spring will have from 13 to 15 coils and be approximately six inches long. Bend the coils apart after forming the spring to achieve this length.
One side of the magazine body should have seven or eight staggered 3/8 inch holes drilled about 1/4 inch apart. These not only serve as a visual indicator of how many rounds the magazine contains, but also enable the spring to be compressed and held in place while the follower is inserted. To accomplish this step, the spring is first inserted into the magazine body. Then, using a screwdriver, punch, etc., the spring is compressed down into the magazine body far enough to allow the follower to be
slipped into place. A punch or heavy wire inserted through one of the clip's top holes keeps the spring down while the follower is inserted over the top of the spring through the cut-out section just below the magazine lip.
Disassembly is done in reverse order by pressing down on the follower, and holding the spring down through one of the holes while the follower is pulled out from just below the magazine lips. When the tool holding the spring down is withdrawn then, the spring will be free to be removed.
The frame is a welded assembly consisting of a folded sheet steel upper section with its ends welded in place. To form the grip frame and magazine housing, steel front and aft sections are welded to the upper frame. The trigger guard, bent from a formed sheet metal strip, is also welded to the upper frame.
While I would prefer this entire frame assembly to be machined from one piece of solid steel, I have utilized the sheet metal assembly described here simply because it can be fabricated with hand tools and a simple welding set-up. A milled steel frame would require a vertical milling machine as well as several formed cutters, equipment beyond the reach of most home workshop enthusiasts.
The sheet steel used to make the frame assembly should be at least .100 inch thick. Slightly thicker, or up to .150 inch, would be even better. Automobile and light truck frames contain suitable material for the frame, although in most instances, it is slightly thicker than necessary.
Start the upper frame assembly by cutting a template to the shape of the given pattern. Transfer the pattern to the sheet steel and cut to shape by sawing and filing. Do not cut the openings for the magazine and trigger until after the forming operation, since the steel in these areas adds to the stiffness of the bottom during bending. While it is possible to use two side sections welded to a bottom piece to form the square-cornered, U-shaped cross-section required, it is considerably easier and the assembly is stronger when bent to shape from one piece.
To maintain uniform inside dimensions, you must bend the frame blank around a form block. This form block is simply a block of steel with the same width as the inside frame, or .600 inch. It should be at least five inches long and .750 inch or more deep. A suitable form can be made from 5/8 inch x 3/8 inch bar stock by reducing the width a uniform .025 inch (that is from 5/8 inch [.625 inch] to .600 inch) and rounding the lower edges slightly.
The completed frame with hammer assembly and magazine latch In place. Note that Its lower portion Is matted, both to provide a non-slip surface and improve appearance.
Assuming that a big enough vise is available, the frame can be bent to shape by locating the middle portion of the blank directly over the .600 inch wide rounded edge side of the form block and clamping both pieces together in the vise. The upper side of the form block should be flush with the top of the vise jaws, with one side of the frame blank extending above it. Also, the form block should be supported from its under side, to prevent it from being driven deeper in the vise jaws as the frame blank is bent to shape.
Another heavy block of steel slightly longer than the form block is then placed against the side of the frame blank, and allowed to rest on top of the vise jaw. Use repeated blows against this block with a heavy hammer to bend the frame blank over. When the side is bent to a right angle, both the form block and frame blank are turned over, reclamped in the vise, and the other side bent to shape. The strip of metal extending from the bottom front is next bent to the contour of the front of the frame sides, and the two seams welded.
If you expect to build more than one of these frames, or if you want a more professionally finished job with straight, sharp corners on the frame, I suggest that you also make a female forming die. This die will accept the forming block and the frame blank, forming the frame to shape when squeezed properly together.
Make the female die just wide enough to accept the forming block plus the double wall thickness of the frame blank, plus another .005 inch to .010 inch for clearance. Bevel the inside upper corners of the female die slightly. A suitable female die can be made by welding or bolting two sides to a bottom section of the proper width, as was discussed in greater detail in the chapter on magazine manufacture. The exact same methods are used here except that the side material must be heavier to withstand the strain of bending the heavier steel used for the frame.
A slotted end cap must be made to slip into the extreme rear end of the frame opening, where it is welded securely in place. Make this plug, which also serves as a rear slide assembly retainer, and the front slide assembly retainer, from .600 inch thick steel. They should both be made from better material than the frame stock since the retainers are subjected to a great amount of shock each time the gun is fired. Farm implements like plow beams, disc and tiller frames, and drawbars contain excellent steel for use in these parts; and if you are fortunate enough to find a piece of a broken leaf from a crawler-tractor equalizer spring, you will have the very best steel available for just about any part of this gun that you care to use it for.
Bevel the edges that will be welded on both of these retainers, because the welds must penetrate as nearly through the edges as possible. Using an electric arc welder, or heli-arc machine, and the smallest electrodes available (which are easier to use in the limited space
available), proceed to weld the rear plug in place. Welds are made around the bottom, back, and top on each side of the plug. Any welding on the front side must be confined to the retainers' extreme top and bottom corners to make sure the slot for the slide assembly is not interfered with. Install the other retainer at the forward end of the frame in the same manner, except make the welds along the back side and at the top end across the bottom on both the front and back sides.
Many times when one welds small parts in place with an arc welder, pits and burns are left on the exposed surfaces which cannot be entirely removed. These are usually made when the arc is first struck. A carbon rod, such as a dry-cell battery electrode, can be clamped adjacent to the seam being welded, and the weld started by striking the arc on this carbon rod. Not only does this trick help to prevent blemishes, it also allows the operator to see what he is doing at the very beginning of the weld. Neat, clean, solid weld joints and seams require quite a lot of experience and ability to accomplish well. Unless you are an experienced welder, I strongly urge that you obtain the services of a qualified operator to do this welding. Here again, try to find someone experienced in welding small parts and thin steel. The average heavy-equipment maintenance welder will only burn up your more delicate assemblies.
Scribe a center line on the frame's bottom side and lay out the openings for the magazine, trigger, and hammer as shown on the diagrams. When precisely located and marked, drill interconnecting holes along theseopenings, and remove these sections of the steel. Finish with files.
The front and rear uprights forming the magazine housing are made from the same sheet steel as that of the upper frame. Form the front part to an inside radius that will allow the magazine to mate closely with it. One good way to make this radius is to turn a section of drill rod to the same diameter as the rounded front side of the magazine, and bend a strip of sheet steel around it. If necessary, construct an outside forming die by drilling-out a 31/2 inches long section of discarded rifle barrel to the correct diameter, then cutting the barrel in half lengthwise. This will give you a rounded trough into which the sheet steel strip can be force-formed to shape.
Make the rear section of the magazine frame in the same way, except that here a rectangular inner opening is required with an inside width of .450 inch. This can be formed to shape in the same manner that the upper frame was, with the aid of forming dies. It is also practical and safe to make this rear section by welding two sides to a middle strip. Allow a lip to extend forward on each of the sides to guide the magazine body. If the welding method is used here, do it from the inside rear, since square, smooth corners must be preserved on the sides adjacent to the magazine body.
An enlarged view of the top of the frame. The hammer spur Is visible at the receiver assembly will be hand-fitted and finished together. This the frame's rear, as is a slot for hammer clearance. Later, the frame and will ensure a good, tight fit between receiver and frame.
The front section is next clamped in its place with its upper end extending into the upper frame. Weld this piece to the upper frame, around its front and sides, both inside and out. Then the rear section is placed in position and welded. That step is most easily accomplished by placing the male forming die from the clip assembly procedure inside the rear magazine housing section. Use this as a spacer while the rear section is tack-welded in place. It can then be removed and the welding completed. A short section of steel is also welded between the front and rear sections on each side at the extreme lower edge. These serve as braces and spacers for the magazine opening.
Cut a strip of the same sheet steel used in the frame assembly for the trigger guard. It can be .375 inch to .500 inch wide and 2.750 inches to three inches long.Bendto approximately the shape shown and weld it in place on the frame.
Should these welds be built-up on both sides, a rounded fillet can be formed of them with a round file. Properly done, this step considerably improves the finished appearance of the pistol.
All welded joints and seams are ground and filed to a contour which blends into the shape of the frame. The inside of the magazine opening must be smoothed and free from burrs and ragged edges. Poor finishing here will prevent proper seating of the magazine.
The sides and ends of the top of the frame are filed to the
same radius as the receiver, permitting a close-fitting joint between receiver and frame. After the receiver assembly is completed, it can be fitted to the frame by spotting and filing.
Scribing the layout lines on the tubing that will serve as your receiver is done most easily with the help of a lathe. Here encircling lines are scribed by hand-rotating the mounted tubing against a sharp-pointed lathe tool.
Chapter Five Receiver Assembly
The receiver assembly is a self-contained unit composed of an outer body (referred to as the receiver), an inner sliding assembly (the slide) containing a breech block, firing pin, and extractor, a barrel assembly, recoil spring, and barrel retaining nut.
Both the receiver and slide body are made from seamless steel tubing, if available. Many light aircraft engine mounts are made of steel tubing suitable for these parts, as are motorcycle frames, certain automobile steering mechanisms, boiler pipe and other high-pressure pipe. A section of 16 gauge shotgun barrel is suitable for use as the slide body. The dimensions shown in the drawings and given in the text were improvised in accordance with the sizes of material available to me when I built the prototype gun. The dimensions given here should be improvised to coincide with whatever size tubing is available to you. If such is the situation, be certain that the inside diameter of your slide body is of sufficient diameter to clear the barrel and recoil spring.
To construct the receiver, use a section of tubing 6.100 inches long, one inch in outside diameter, and with a wall thickness of .080 inch. A center line is laid out and scribed on the top and bottom and on both sides of the tube, dividing its length into four equal quarters.
These center lines are easily marked if you have a metal lathe to use by placing a sharp-pointed lathe tool exactly on center in the tool post of the lathe. Center the section of tubing in the lathe's chuck, with the tail stock's center in the opposite end. With the pointed tool bit digging lightly into the tubing, it is drawn lengthwise along the lathe carriage, thereby marking a clean, straight center line. The tubing is rotated 90 degrees and the process repeated until all four center lines are marked.
The ejection port is laid out on the receiver tube's upper right side. Its front edge is 3.150 inches from the front or muzzle end, and its bottom edge .200 inch above the
Longitudinal lines are marked by drawing the lathe tool/ carriage along the stationary work mounted In the lathe.
center line. Make it one inch long and .600 inch wide. That should be ample to allow the empty cases to eject without interruption. Also, cut out a portion on the tube's bottom side, to clear a space for the magazine. The front edge of this slot is located 3.200 inches to the rear of the front edge. When finished, the space must be .460 inch wide and 1.500 inches long, centered on the bottom center line.
Two slots are cut out next, centered on the three and nine o'clock center lines, 1.100 inches deep by .500 inch wide, measured from the receiver's rear edge. The raised checkered portion of the slide will rest in these slots.
Shape the receiver's rear end to the slightly concave angle shown in the drawings, primarily to streamline and improve the appearance of the finished weapon; the exact shape is not too critical.
A pair of retaining lugs must be shaped from bar stock and welded in place centered exactly on the bottom line. Both lugs are .600 inch wide (which is the inside width of the frame) and shaped as shown in the diagrams, except that enough extra material is left on the front side of the forward lug to allow a hole to be drilled completely through both sides of the frame and the lug. Clamp both assemblies together when drilling this hole. The pistol's takedown latch fits in this hole, and if the front portion of the front lug is removed prior to drilling, the drill will crawl or drift, causing misalignment. After this step is completed, trim the front of the lug by sawing and filing.
The rear lug is shaped to its finished size before installation except for the notch at its extreme rear, which is left slightly undersized to assure a close fit.
Be sure to bevel the upper edges of the lugs before welding them, so that the welds penetrate completely through to their centers. If at all possible, use a heli-arc welder here. These lugs take a considerable shock when the pistol is fired, so the lug welds should be as strong as possible.
A discarded shotgun barrel in either a 16 or 20 gauge is a good source of tubing to build the slide body from. Cut a six inch section of the barrel, beginning just forward of its forcing cone. The barrel is sufficiently thick there to permit lathe-turning the barrel to a uniform outside diameter. If the 16 gauge barrel is used, it will have an inside diameter of around .662 inch or slightly larger than required. The 20 gauge barrel, on the other hand, has a bore diameter of about .615 inch and will require some slight reaming.
Turn a steel collar to fit inside the front of the slide body. Make it .300 inch thick and bore the inside to a diameter just larger (.005 inch - .010 inch) than the pistol's barrel diameter.
A section from the chamber end of a barrel to a '98 Mauser or .03 Springfield works very well for this collar. Since the 30/06 or 8 mm chamber is already nearly a half-inch in diameter, it doesn't require much reaming to make the pistol barrel slip into it. Then the outside of the
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