Cabot makes guns out of a ton of exotic and random materials. Most are for decorative purposes. The materials used probably aren't the greatest for durability and reliability, and for hard use (i.e. military and law enforcement purposes). That said, they'd still need to be able to shoot for some duration and if the material was so bad that you can actual shoot the gun without serious problems, then they probably wouldn't make it with that.
Anyway, maybe I need to get more granular with my question. Below is a chart showing the various specs for AISI 4340 steel (assuming that this is the exact type of steel used in guns). Does anyone know what the ideal values are for each property?
https://i.imgur.com/AckcmMW.png