Gunsmithing Type of Metal on Matte Savage Bolt Handles?

[ridgeway]

I've turned down a few SS and Blued Savage bolt handles in order to thread and install a custom bolt knob and they machined OK. I set up a matte finish knob and went to machine it and HSS would not come close to touching it! It almost seems like its case hardened? I stuck my huge 3/4" carbide tipped turning tool and was able to cut through the surface. After that, I was able to cut with HSS fine. I can't even break the surface with a file!

What kind of metal are they made out of? I find this problem with matte finish handles. Anyone have similar experiences?

 

[Capt Beach]

Unobtanium

 

[geargrinder]

I believe they are a scintered metal. Like their triggers.

High pressure on a powdered material to form the finished product. End result is much like case hardening, hard outer surface softer material underneath.

 

[ridgeway]

It seems like hit or miss with them in terms of machinability. I did a stainless knob yesterday and it killed a nice hertel HSS center drill. I faced a bit deeper and it was fine. Did another stainless one today, it cut and machined like a dream! Guess with cast, you get all kinds of stuff! Good thing for carbide...I got some carbide center drills now, lol