to tell the truth i never seen a RL jackhammer before. but i think its realistic...only not available yet like the OICW or whatever. but anyway....jackhammer is good if ur playing insurgents but sucks if ur playing US/Chinese since they both got a better shottie. and to tell the truth, i never use jackhammer since everytime i play engineers i always use tanks or APCs.

the only downside bout jackhammer is that the reload time is too long if u compare it to regular shotties. and the dmg is also lower than regular pump-type shottie.