All good info above. I used to fly high power in the early 90's, before most of it was regulated. I was a Tripoli member, they are the ones to contact for good education. As stated, bigger is certainly better, but the price goes up faster than the rockets do. It's a contagious hobby, the bigger you go, the bigger you want to go. Reloadables were just getting started when I was flying, and hybrid propellants were starting development. The largest I ever flew was a L motor, but J and K were what I flew mostly. Back then you didn't have levels to qualify for. You flew an 'H' under supervision, and then you could go as big as your wallet allowed.
I enjoyed building about as much as launching. If it's still in print, find a copy of Peter Alway's book,
Rockets of the World. It has diagrams and dimensions of practically every sounding rocket and launch vehicle ever made from the '50s on. Perfect for building scale, which was what I liked best. The Honest John I have over my shoulder (this picture is 20 years old) was scaled up from the Estes kit, with reference to the Alway book. It's 1/4 scale, scratch built, and could use 38mm and 54mm motors. It would reach 8000 feet on a K550. The smaller model is a 1/5 scale Black Brant sounding rocket, also built using Alway's book. It had a 38mm mount and could use anything up to a K. I got over 10,000 feet with a K550, I had a radio beacon in it to help locate it for recovery.
