> A stamping machine isn't particularly easier to come by than a good boring machine, in my opinion. A basic shop press which is sufficient to stamp AK receive

> A stamping machine isn't particularly easier to come by than a good boring machine, in my opinion. A basic shop press which is sufficient to stamp AK receivers can be had for under $200. That's not even in the same league as basic CNC equipment, and hardly out of reach for anyone that decided they wanted to homebrew a receiver. >I completely disagree with that. As 0x12 also notes, you're being hugely optimistic about the material sciences involved. Even when using steel, barrels are either milled or hammer-forged, not cast, to achieve sufficient strength. Even when you're talking about small parts, like extractors, MIM[1] parts are absolutely notorious for being prone to breakage or being out-of-spec. Color me highly skeptical that plastic-based additive printing is going to catch up to or surpass what we know about metalworking any time soon. [1] http://en.wikipedia.org/wiki/Metal_Injection_Molding http://en.wikipedia.org/wiki/Metal_Injection_Molding