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.125" Barrel Locating Pin Drill with //31 drill, press pin into hole.

.125" Barrel Locating Pin Drill with //31 drill, press pin into hole.

n I Barrel.

allowing you to perform the entire chambering operation with a single reamer. The cheaper ones often require the additional use of a separate reamer to cut the throat portion. In most cases the higher priced reamers, such as those made and sold by Clymer Manufacturing Company, will prove to be the cheapest in the long run.

The barrel proper is rather simple to make. Cut a section of the barrel length to the desired length (it isn't written in stone that this barrel must measure exactly 6 inches) and square the ends in the lathe. Turn the breech end to a diameter of .875 inch for a length of 1.125 inches. Directly in front of this, form a flange .100 inch wide and 1 inch in diameter. The remainder is turned to a diameter of .600 to .625 inch, as you prefer.

The breech end of the barrel should have a 45-degree approach cone to facilitate feeding. With such an angled approach cone, if the cartridge ever moves far enough forward for the bullet to contact the barrel, it will be guided into the chamber without the stovepiping or hangups common in other designs. Crown the muzzle end by using a lathe tool ground for the purpose. Both the crown and the breech cone should be polished to the highest degree attainable, using progressively finer grits of abrasive cloth or paper.

Determine chamber depth by measuring the distance from the front face of the receiver to the bolt face with the bolt held forward as far as it will go. The breech end of the barrel is also measured from the end of the approach cone to the flange. This length is slightly longer than the first measurement, so subtract the first measurement from this one. The result will be the depth of the cartridge head below the end of the approach cone.

Cut the chamber by feeding the chamber reamer into the breech end of the barrel with the barrel chucked in the lathe while turning at the slowest speed available; pressure from the tail stock ram will be used to feed the reamer into the bore. Do not attempt to hold the reamer in a rigid tail stock chuck. Keep it from turning through the use of a hand-held tap wrench, clamp, small wrench, or some similar arrangement that can be released and allowed to turn with the barrel in the event the reamer should suddenly decide to seize. Keep the reamer well lubricated, and withdraw and clean frequently. As you approach the finished depth, clean the chamber and check your progress frequently. When the measurement between the chambered case head and the barrel end coincides with the previously established measurement, it is time to stop. Another method is to secure the barrel by clamping it between blocks in a vise. Then turn in the reamer by hand using a tap wrench or reamer drive. If this method is used, care must be taken to hold the reamer straight, in line with the bore, with no side pressure exerted in any direction.

Drill a hole, as shown in the drawing, to allow a locating pin to be pressed into it. This ensures that the barrel is located in the same position each time it is removed and replaced. This pin fits into a matching slot cut in the threaded end of the receiver. The hole is drilled with a #31 drill and a slightly tapered 1/8-inch pin pressed into it. Care should be taken nor to drill into the bore.

Locate a slot to clear the extractor by coating the extractor front face with some sort of marking compound such as lipstick or Prussian blue and, with both barrel and bolt installed in the receiver, pushing the bolt forward against the barrel. Remove the barrel and the resulting imprint left by the marking compound will show the location of the slot to be cut. This can be cut either with a milling cutter or the hand grinder.

If the time should ever come when commercial barrels are no longer available, we will have to make our own. A method for doing this is included in Vol. I.

Machine Pistol PhotosCutting Barrel Feed Cone9mm Assault Pistol

Right: Approach cone is cut using compound feed.

Below Right: Finished barrel.

Below: Barrel in place is secured by being threaded on barrel shroud.

Bottom Right: Locating pin can be pressed into barrel hole by using a vise, as shown.

9mm Handguns Table

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