Used Estes C6-3; and it rose up beautifully.  Arced over a bit and after apogee t' charge blew t' rocket apart.  I had made sure with a poke test that t' parachute wasn't too tight, matey, but t' charge made t' rocket come down in 5 pieces (nose, me bucko, parachute, body, motor, ya bilge rat, motor retainin' ring). Blimey!  I think it was a certain lot o' C6s I had (from Estes Blast Off Flight Pack) with too much ejection charge. Blimey!  Broke a body fin on landing, arrr, but will fly again...maybe after some modifications.