yep, actually the renewed wiki page states its type as bullet. It means though, that you have hit that baron 50 timers normally, halving the shield and its resistances, then finally dealing a little more than 1 damage per hit, and he probably used a medpak in between, otherwise the armor should get dropped being worn down to ~30%.
I recall me playing 0.9.9.5 AoMr and fighting a hell knight with 2x2d4+3 speedloaders, that knight soaked a helluva bullets, and dropped me a "gothic armor" at 150%. Grrr.