They are massive threatening creatures that are more than capable of withstanding a lot of ballistic and blunt trauma, evidenced by one having barbed wire and an axe lodged into it with no ill effects.
The virus has caused the Ragers to gain more muscle mass, their weights easily coming close to that of the largest recorded uninfected bears.
They have very acute senses of hearing.
Due to their high ability to deal and absorb a lot of damage, it is a good idea to keep distance from the Rager. As will all Freaers, the Rager is suseptible to being set on fire which will stun it and temporarily slow it down. Shotguns are also effective at killing Ragers.