Aluminum Barrel?
I believe Scandium is classified as a rare earth element and can be found in group 3 on the Periodic Table of Elements which also contains the element Aluminum, probably giving the 2 metals similar properties.
Scandium is alloyed with Aluminum in ratios of .5% to 1% Scandium giving it a greater strength, particularly when welding. It has been used in the Areospance industry, particularly in the Russian Mig 21 and 29, Baseball bats, bycycle frames and by ONE firearms manufacturer, Smith and Wesson for the manufacturing of frames.
And no, I don't believe I would want to own a .357 magnun with the frame and possibly the barrel manufactured using an alloy containing as much as 99.5% Aluminum, regardless of the hardening properties of Scandium. I guess I'm just old fashioned.
F. Prefect