Your Grenades stick to Ogryns and Monstrosities. 6-15% Damage vs Ogryns and Monstrosities
5-8% Strength for every shot fired during continuous fire. Stacks 5 times.
Build template for splodie Ogryn - when you just want to watch the world go BOOM~Big Boom does affect Rumbler, and all Heavy attack talents (bleed, toughness e.t.c.) affect Rumbler special. A few slaps of the rumbler and everything bleeds to death.