I'm not sure of the speed related with the concussive blast from lightning. I suspect super-heating air to a 10,000+ deg F plasma in nanoseconds may be enough to do the job... so I'd guess "yes".

Besides, there is enough total energy in a bolt of lightning to outmatch quite a bit of C4.

according to the link below, a bolt of lightning has ~10^10 Joules of energy... or the equivalent of ~1 TON of TNT... (wow)

http://www.vendian.org/envelope/Temp...RL/energy.html