confirmed!
I'm thinking since the majority of sound produced is due to super-sonic ball cracking sound barrier, this experiment could be done to find "loudest length"...it should tie very closely to the "fastest ball" barrel's length.
Fun to experiment, who doesn't like science? I have nothing with a "short barrel" (sub 18nchange inches) but, will def. attest to longer=quieter in the 18"-24" barrel range. Not as easy to notice with CB's as it is with the zippier stuff.
Seriously, firing a CBlong in my Cooey 75 makes 2 distinct sounds...click of action and, thwack of ball's arrival.