Just found this on the Chuckhawks site:
"Most quality chokes today are of the conical parallel variety, meaning we have a tapered conical section that gives us the desired constriction or squeezing effect on the payload, followed by a straight section that is parallel with the bore, containing no taper. After the initial forcing cone area, the parallel section tends to align and stabilize the payload before it exits the muzzle. It is this parallel section, particularly an extended parallel section, which has typically given the best patterns with heavier payloads, larger shot and steel or no-tox shot. "
and
"By closing the fingers in an attempt to give more choke effect, it creates a steeper taper. After that taper, there is no parallel section, out of the muzzle flies our shot cloud. Rather than a conical-parallel type of choke system, the Poly-Choke is actually a conical only choke, with a conical section the same length at all times, but varying taper. I believe is it the complete lack of a parallel section that contributes to the poor performance I experienced in the course of this review."
Fellow by the name of Randy Wakeman wrote it. He claims that he spent lots of time and money on the subject.
Since trimming a barrel back effectively eliminates the parallel section Mr. Wakeman is writing about, there is a good chance my "bobbed" barrel will shoot less cohesive patterns.
