Do people really use carbon fiber in armor? I know the Army tried glass fiber and Kevlar for helmets before choosing Kevlar (and now some UHMWPE as well), but I can't remember anything about carbon fiber. I know you can buy carbon fiber helmets and part carbon fiber part Kevlar and/or UHMWPE helmets (at least in theory, there are problems with massive (multi year!) lead times and MIL/LE only items), but they always had dubious protection from ballistic projectiles, regarding back-face deformation, splintering, cracking, spalling, pass-through, etc.