--- my favorite explanation of how choking works is by deflecting or accelerating the pellets inward, as they hit the constricted area. Something like hitting the rail at a shallow angle, on a pool table. If this were so, we would discuss the taper angle and not the constriction or taper length.
Opening chokes with a reamer leaves a parallel section, length depending on how much constriction is removed. I have not observed this to be a problem. The resulting patterns seem to match what the finished constriction would suggest it should, regardless of how long the parallel section turns out to be (within some fairly few inches limits, IMO). Theoretically, at least, if the parallel was long enough, the resulting patterns would be cylinder (I agree with this). I have not observed this. Like Miller, I believe a continuous taper, from chamber to muzzle, WOULD result in cylinder patterns (agree). I remember reading that this was tried, in the early development of chokes for muzzle loaders, and the results were cylinder. In order for choke to work, it obviously needs some abruptness. I have some unanswereed questions on taper angle. If not for the experience with the Hellis 7" full, I might agree. I think more importantly, short taper length is not a mark of poor workmanship or design. Short taper length seems to work just fine. But, I suspect you could get too short!
