No 77 Phosphorus is a British gas grenade in Post Scriptum. It contains 8 ounces (approx. 226gr) of white phosphorus and provides a large smoke screen when detonated. Firstly note the weapon uses an All WaysImpact fuze (much like the Gammon Bomb) meaning upon impact it will detonate. Secondly note white phosphorus has incendiary properties and will damage friend and foe alike, if they are unlucky to be caught in the initial explosion. Caution is advised when deploying this grenade.
The smoke lasts about 26 seconds.