I have been working with the exact same composite materials offered by SW's. I do not have the exact strength and fatigue numbers on hand but I can tell you what I have learned while handling, machining, finishing and coloring this metallic witches brew.
It is a true composite, composed of S.S. alloy 420 and a tin bronze infiltrant (not sure of the CDA#)
It is somewhat brittle, but has a better tensile strength than grey cast iron. Kind of like malleable cast iron. Thin sections will yield a little bit before fracture. This material is nothing like forged/ rolled material.
It is quite abrasive and rather difficult to machine. Carbide tooling is really a must.
It has poor heat conductivity. But this is a plus if it needs to be soldered or welded.
Silver bearing hard solders flow well and penetrate to fill small voids. I use "Black" paste flux. It can also be welded via TIG. I've not done strength tests and would only use these method for cosmetic repairs or dovetailed joints.
I have seen prototype turbine rotors used in real test scenarios. But gun parts? Maybe for lever type applications? Probably a bad choice material for sliding surfaces or any part subjected to high impact or sudden pressure.
Hope some of this helps. I'll dig up some test specs to post soon.
-G