(Replying to PARENT post)
Btw, you need a rifled barrel to make accurate shots at long-ish distances. For close quarter combat a submachine gun with a smooth bore would do quite well. Something similar to this: https://en.wikipedia.org/wiki/Borz. Any machine shop can crank those out in numbers.
(Replying to PARENT post)
I'm going to argue the point. Yes, your average suburban weekend warrior won't have the stuff. But if you are even slightly into machining, you almost certainly can.
Practically every machining magazine will have at least one article about rifling in every issue.
Yes, you need a metal lathe and some tooling. Those are neither rare nor that expensive--and very old lathes and tooling work just fine.
The biggest problem a machinist always has is space for the equipment.
(Replying to PARENT post)
(Replying to PARENT post)
Ehhh ... you talk a lot about 3D printing, but that’s not the only tool that people have in their garages. A huge number of people have metal lathes in their garages. I happen to have a small, CNC controlled metal lathe and mill in my garage. The whole setup cost me about the same as a high quality, rapid prototyping 3D printer (<4000USD). I am pretty sure I could make a firearm, in my garage, including rifling, if I was determined to do so.
Personally I have no desire to build my own firearms, because it’s illegal to do so in my country and it’s also extremely dangerous. But in many places in the US it does appear to be legal.
(Replying to PARENT post)
I guess this is all a long winded way of saying the 3D printing panic is both right and wrong but neither side is looking at it in a factual way.