>I've always found it interesting that AKs are relatively easy to manufacture in rough conditions, but that ARs are easier to manufacture in the US. I can build

>I've always found it interesting that AKs are relatively easy to manufacture in rough conditions, but that ARs are easier to manufacture in the US. I can build a working AR lower receiver in the US with tools I have laying around my home (drill press, rotary tool, etc). I can't do the same for an AK because I don't have a spot welder to attach the rails. Worse than that: AK receivers have to be stamped, rails welded on, then heat treated. A soft AK receiver will run for a while but eventually waller out all the pin holes. The gun will get more and more rattly until it can't completely chamber a round, at which point it will blow up. The heyday of the stamped sheet metal gun was, of course, WW2. The Sten, MP 36, M3, and postwar AKM, CETME, G3, etc etc. The central planners were staring down the barrel of total war. They were thinking they would have to arm every single man, woman and child in the country. The Brits made four million Stens, at about $150 each. For that, you want as few machining operations as possible, but you can spend on the tools themselves, since they'll be amortized over huge production runs. Therefore you see heavy industrial processes with specialized tools: 100 ton presses stamping out 20 receivers at a time, specialized heat treat ovens to make up for the downsides of metal stamping, complex assembly jigs, etc. The AR pattern rifle is unattractive for super-mass production. Milled receivers with curved surfaces and finicky blind holes. But it's not a stressed component, so you can make the damn thing out of plastic if you want, and none of the dimensions are safety critical, since the barrel is self headspaced with bolt lugs built in. (The US could put complex features into the barrel because they could trust their subcontractors to build interchangeable parts-- the Sten had magazine feed problems the entire war because of contractors going off spec and the Soviets had innumerable problems with QA. If you can't trust outside firms then you have to build everything in house) This means when you shoot out the barrel in an AR, your unit's armorer can put in a new one. If you wear out the barrel in an AK, you throw away the gun-- headspacing is a factory operation, and the Red Army isn't going to waste time transporting trash. Official doctrine on the US M3 was to provide no replacement parts. The whole gun was welded and riveted together. You could clean it, but otherwise it was a disposable unit. Heavy industrial processes are cheap, but not amendable to field repair.