Can I make a firearm with it?
Probably.................
“Can I make a firearm with it?
“
Different materials have different “strengths.” Concrete, for example is good in compression, but of zero worth in tension. My guess is no, unless it is heat and shock resistant. The barrel of a gun heats up and a material that might make a great chassis for a car might disintegrate with the sudden changes in temperature even if it could withstand the pressure.
One thing you might do with such a material is create a vehicle covering similar to paint that is full of tuned cavity resonators that capture radar and dissipate it without returning an echo.