If Warsaw Uprising Polish resistance fighters could build working STEN-like submachine guns under the watchful eyes of the Nazis over 70 years ago, then I suppose even a Hawaii-born shade tree gunsmith could do at least as well.

As I've pointed out (in vain) to six readers here who staunchly support the fantasy that an official prohibition of firearms can always be equated with increased safety for all, then our major U.S. prisons should all be havens of tranquility, with little or no chance of murder, physical assault, intimidation or rape.  But are they?  For those who care about such things, there was a celebrated case of an American prison inmate who managed to build himself an electrically primed and repeating handgun using homemade metallic cartridges, all while under the supervision of prison staff.  I would guess had he been so inclined, a prison-made late medieval style longsword (as popularized by Aragorn, son of Arathorn in the LotR movies) would have been child's play too.