Yeah, Firepower doesn't have to worry about US laws and is in real need for SD weapons (more so than most of us).
Anyway, you don't NEED a lathe to cut a shotgun barrel. There is no science to it other than making a tube shorter, but you need to make the cut as square as possible and de-burr the cut when you finish. You can cut it near perfect square with almost any metal chop saw and a good vise, or by clamping a piece of channel iron (with the end squared) to the barrel and using it as a guide. If this were a rifle barrel, I would be less likely to recommend these techniques. A SBS with a practical effective range of MAYBE 25 meters? It'll work just fine doing it minus a lathe.
Anyway, you don't NEED a lathe to cut a shotgun barrel. There is no science to it other than making a tube shorter, but you need to make the cut as square as possible and de-burr the cut when you finish. You can cut it near perfect square with almost any metal chop saw and a good vise, or by clamping a piece of channel iron (with the end squared) to the barrel and using it as a guide. If this were a rifle barrel, I would be less likely to recommend these techniques. A SBS with a practical effective range of MAYBE 25 meters? It'll work just fine doing it minus a lathe.