actually they do break.....but only if your us!!
we got a bad batch of firebolts installed on the team sp8s - the "fins" between the head and tail had been over milled, and the sustained high ROF in Mahlwinkle for 3 days play took its toll.
needless to say we weren't amused, and its never happened again!! ours are the only cases of failing firebolts we've heard of......typical!