Shop-made Barrels

Home manufacture of firearms is older than the United States itself. Before the Industrial Revolution, artisans with specialized skills produced most manufactured goods and gunsmithing was among them. Rigid, metal lathes along with a power source to run them were instrumental in building the tools necessary to spawn the ability to manufacture en masse.

Home gun making today is part tradesmanship curiosity (the satisfaction of making something yourself, even if you could have simply bought it) and part political statement (the satisfaction of civil disobedience toward authoritarianism). A "ghost gun" is madeup phrase describing certain prefabbed gun parts intended to frighten people unaware that hardware and industrial supply stores exist.

It’s especially amusing in light of the fact there aren’t restrictions against owning lathes and mills which are the engines of modern manufacturing, can fit in a home garage or shop, and can be used by a knowledgeable machinist to make nearly any metal component desired. Of course, "knowledgeable machinist" oversimplifies the time and effort it takes artisans to make quality parts.

Just because a machinist or gunsmith can make apart on a lathe or with a file doesn’t mean it isn’t preferable to just order it if available at a reasonable price. Like a semi-inletted stock, using a partially completed receiver moves a project along. The focus of late has been on receivers largely because the BATFE can’t follow its very own declaration of what constitutes apart that is 80% complete.

Barrels don’t receive the same attention because their sale isn’t restricted by law—at least not in the United States, at least not yet. But what if they were? There’s nothing trivial about making quality parts but barrel making is another thing entirely. Even "chip makers" (companies that produce their own components in house) still tend to outsource barrel manufacture.

Even as 3D printing and Computer Numerical Control manufacture is reaching home/hobby price points and greatly improving, making your own barrel might seem out of reach. However, there is away. Electrochemical machining (ECM) is a method of machining metal workpieces through the anodic dissolution of metal. ECM can cut external and internal geometries of small or odd-shaped angles, intricate contours, or cavities even in hard and exotic metals.

Based on electrolysis, a positively-charged cutting tool is connected to a direct voltage source advanced into a workpiece acting as the anode with a negative charge. A charge exchange between them in an aqueous electrolyte solution targets specific areas of the workpiece. ECM uses controlled electrolysis to erode metal in a pattern that we can control and is essentially reverse electroplating in that metal is removed instead of added.

High current is passed between an electrode and the workpiece with removed material precipitated from the electrolyte solution in the form of metal hydroxide. The components are subjected to no thermal or mechanical stresses. Precision cutting on internal geometries is exactly what is needed for barrel making. Barrel stock can be made from hydraulic tubing. With ECM, this can be pre-hardened as no annealing will be needed when the rifling is complete. A boring rod can be made from bare metal bar stock.

Other than common items available at any hardware store (hoses, clamps, buckets, etc.) the manufacturing components consist of a fixture, rifling mandrel, chambering insulator, chambering offset, throating offset, and end pilot. All of these can be made on any 3D printer using PLA+ (polylactic acid) filament and needed. STL files to make them are readily available for download. Not counting the 3D printer, this reusable tooling to make rifled barrels can be had for about $100 in component costs.

Accuracy tests of 9mm pistol barrels made this way have found them capable of shooting 2.5-inch groups at 25 yards, more than serviceable for a service-grade handgun. Google "ECM Barrelmaking Shopping List" will readily locate the resources needed to get started. And should you decide to give this a try, American Gunsmith is happy to pay you to publish an article about your results! AG