Looks like CO2 engraving. But it Ain't a fiber.... A WORLD of difference. I did several of my guns and the CO2 marks, but just not good enough. At least for me.
Woodworking, Old Tools and Shooting
Ray Fine RF-1390 Laser Ray Fine 20watt Fiber Laser
SFX 50 Watt Fiber Laser
PM2000, Delta BS, Delta sander, Powermatic 50 jointer,
Powermatic 100-12 planer, Rockwell 15-126 radial drill press
Rockwell 46-450 lathe, and 2 Walker Turner RA1100 radial saws
Jet JWS18, bandsaw Carbide Create CNC, RIA 22TCM 1911s and others