Scandium would be nice....
Muttley, a couple of years back a youngster majoring in machine trades asked me about getting blueprints and machinist's working drawings of a M1928 Thompson for his graduate project in setting up a numerical control milling machine program. And he had stainless steel in mind for his project's material; he was pretty well heartbroken when I told him the 1986 Reagan *Firearms Owners Protection* law prohibited his swell idea.
The good news is, the beautiful version of the M1891 Mosin-Nagant rifle that resulted was a superb rendition of that design produced in Russia, two US factories and France, as well as several rebuilders elsewhere. And the resulting stainless version, serial number 1,000,000 resulting was both a pretty thing to behold and a good shooter in its own right. But the Tommy would indeed have been nice, and I could probably have hedged a M1A1 version out of him for myself.