All about glass > BRNS Bullet Resistant Glass Classification

If no spall is ejected on the side opposite the shot, the rating is followed by the letters NS

EN 1063
Plastofloat weapon used Calibre ammunitions used shooting
in m.
in m/s
BR 2 NS P 139 handgun 9 mm luger cylindro-ogivale plomb
chemise acier plaqué
5 400
BR 3 NS P 185 handgun 0,357 magnum conique plomb chemisé
acier plaqué
5 430
BR 4 NS P 278 handgun 0,44 rem mag cylindro-conique tronquée
plomb chemisé acier
5 440
BR 5 NS P 345 gun, rifle 5,56 X 45 cylindro-conique plomb
masse pénétrante acier chemisé acier
10 950
BR 6 NS P 375 gun, rifle 7,62 X 51 cylindro-conique plomb
chemisé acier plaqué
10 830
BR 7 NS P 730 gun, rifle 7,62 X 51 perforating cylindro-conique acier
chemisé acier(noyau dur)
10 820

For example P 129 stops a 9 mm Luger shot with a handgun from a distance of 5 metres and is rated BR2.
Moreover, because it protects people located just behind the glass by guaranteeing that no spall is ejected, it is rated BR2 NS.