Last I checked there is, but its incredibly unpleasant (read “nearly impossible”) to set up . Basically you have to break your armature into separate bones and connect them using rigid-body constraints. Alternatively, you might be able to create a ghost ragdoll and just have the armature copy the rotations of its objects using a python script, but this would be even more complicated if it worked at all.
Hopefully a nicer way is coming soon with all the new bullet features and stuff.
I seem to remember seeing somewhere (on this forum) a combination, where the character was surrounded by a ghost bounding box which would switch the ragdoll on for the death “animation” (ragdoll physics). Cant seem to remember what it was called though…