Bob Peters
Well-known member
Being I got a late start in life at shotgunning, I've taken every measure to learn about the subject. The following are quotations from classic books on the subject by authors Thomas, Brister, and McIntosh. Also a quote via Brown from a book on pheasant hunting. It's easy to see that in most situations a more open bore is preferable to one that is more constricted. These various texts were published in the 60s 70s and 90s. For that reason they mainly deal with lead shot, although steel is discussed in some of these books as well. Needless to say if you're shooting an one-eighth oz. load of #22 tss through a .410 at 1900fps you need to write your own book, because tungsten wasn't much discussed in concern to shot pellets then.
"To see the advantages of a larger pattern, consider that choke is in one sense a function of distance, and its purpose is to keep the shot swarm smaller in diameter at greater range. We still define degrees of choke according to the number of pellets that print inside a thirty-inch circle at forty yards. If your favorite quail gun will put half its shot in that circle at that distance, you'd say it had an IC choke and call it a damn good quail gun. And it would be-at forty yards. At fifteen or twenty yards, it's throwing a pattern scarcely larger than a dinner plate, a pattern so dense that a well-centered bird is likely to disappear in a pink mist; so small that a tiny error in gun-pointing means a clean miss. For all practical purposes you're shooting your quail with a full-choke gun. But don't you need the choke for all those forty-yard birds? There are two answers to this. First, if you're an average upland hunter and an average shot, you don't shoot at many forty-yard birds, and you hit only a fraction of these. By far the majority of upland birds bagged in the United States die within twenty-five yards of the gun."
Michael McIntosh, Shotguns and Shooting P. 119
"In summary, IC is the choke to choose if you're selecting a pheasant gun. It will deliver killing patterns in 12, 16, and 20 gauge guns with standard loads."
Larry Brown, From a Pheasant Hunter's Notebook P. 64
"The improved-cylinder pattern, which exposes a higher percentage of its pellets to atmospheric resistance at the muzzle, spreads faster and in more direct ratio to distance[...] the full choke stays tight, then spreads out suddenly, something like the bell of a trumpet, while IC spreads out as a rather constant cone. [...] The significance is that at the distances at which much game is killed, between 20 and 38 yards, the improved cylinder is at its best, offering adequate killing density but at the same time a nice, broad spread to give the shooter more margin for error. Within that same critical yardage the full choke is mostly a tight cluster of center pellets surrounded by a ragged fringe. The full choke's reign of superiority is considerably shorter in useful yards than the IC's. Between 40 and 50 yards, where the full choke shines, even the best of patterns begin to undergo a number of ills... By 55 yards, with ordinary hunting loads, the full choke has become less efficient than the improved cylinder at 40. [...] So what we have here is one choke that is quite deadly for a distance of about 18 yards (from 20 to about 38 with most hunting loads in a 12 gauge) and another that shines for 10 yards or so with the same ordinary load. Moreover, in the improved cylinder's favor, the 18 yards or so yards where it is best happen to be the very ones where most hunters can, and do, take their game."
Bob Brister, Shotgunning The Art and the Science Pgs. 127-129
"Most game[ ] is shot at moderate ranges-say, 25 to 35 yards. ; and at such ranges open-bored guns are well capable of delivering killing patterns. By using heavily choked guns for such work, there-fore, the tendency, taking one shot with another, is to put an unnecessary amount of lead into birds killed with accurately aimed shots, and to miss others which might have been killed by the wider-spreading pattern of an open-bored barrel."
Gough Thomas's Gun Book P. 48
Below the author is discussing findings from a book titled "The Mysteries of Shotgun Patterns" by Oberfell and Thompson
"They find that, for a given number of pellet strikes, the merit-rating of the true cylinder pattern is highest. Thus, a true cylinder makes as dense a pattern at 30 yds. as a half-choke[Mod] at 40; but it will be a better-quality pattern, other things being equal, with fewer patches and less central concentration, and in practical effectiveness will have less than its seeming or nominal disadvantage in respect of range.
Gough Thomas's Gun Book P.160
"To see the advantages of a larger pattern, consider that choke is in one sense a function of distance, and its purpose is to keep the shot swarm smaller in diameter at greater range. We still define degrees of choke according to the number of pellets that print inside a thirty-inch circle at forty yards. If your favorite quail gun will put half its shot in that circle at that distance, you'd say it had an IC choke and call it a damn good quail gun. And it would be-at forty yards. At fifteen or twenty yards, it's throwing a pattern scarcely larger than a dinner plate, a pattern so dense that a well-centered bird is likely to disappear in a pink mist; so small that a tiny error in gun-pointing means a clean miss. For all practical purposes you're shooting your quail with a full-choke gun. But don't you need the choke for all those forty-yard birds? There are two answers to this. First, if you're an average upland hunter and an average shot, you don't shoot at many forty-yard birds, and you hit only a fraction of these. By far the majority of upland birds bagged in the United States die within twenty-five yards of the gun."
Michael McIntosh, Shotguns and Shooting P. 119
"In summary, IC is the choke to choose if you're selecting a pheasant gun. It will deliver killing patterns in 12, 16, and 20 gauge guns with standard loads."
Larry Brown, From a Pheasant Hunter's Notebook P. 64
"The improved-cylinder pattern, which exposes a higher percentage of its pellets to atmospheric resistance at the muzzle, spreads faster and in more direct ratio to distance[...] the full choke stays tight, then spreads out suddenly, something like the bell of a trumpet, while IC spreads out as a rather constant cone. [...] The significance is that at the distances at which much game is killed, between 20 and 38 yards, the improved cylinder is at its best, offering adequate killing density but at the same time a nice, broad spread to give the shooter more margin for error. Within that same critical yardage the full choke is mostly a tight cluster of center pellets surrounded by a ragged fringe. The full choke's reign of superiority is considerably shorter in useful yards than the IC's. Between 40 and 50 yards, where the full choke shines, even the best of patterns begin to undergo a number of ills... By 55 yards, with ordinary hunting loads, the full choke has become less efficient than the improved cylinder at 40. [...] So what we have here is one choke that is quite deadly for a distance of about 18 yards (from 20 to about 38 with most hunting loads in a 12 gauge) and another that shines for 10 yards or so with the same ordinary load. Moreover, in the improved cylinder's favor, the 18 yards or so yards where it is best happen to be the very ones where most hunters can, and do, take their game."
Bob Brister, Shotgunning The Art and the Science Pgs. 127-129
"Most game[ ] is shot at moderate ranges-say, 25 to 35 yards. ; and at such ranges open-bored guns are well capable of delivering killing patterns. By using heavily choked guns for such work, there-fore, the tendency, taking one shot with another, is to put an unnecessary amount of lead into birds killed with accurately aimed shots, and to miss others which might have been killed by the wider-spreading pattern of an open-bored barrel."
Gough Thomas's Gun Book P. 48
Below the author is discussing findings from a book titled "The Mysteries of Shotgun Patterns" by Oberfell and Thompson
"They find that, for a given number of pellet strikes, the merit-rating of the true cylinder pattern is highest. Thus, a true cylinder makes as dense a pattern at 30 yds. as a half-choke[Mod] at 40; but it will be a better-quality pattern, other things being equal, with fewer patches and less central concentration, and in practical effectiveness will have less than its seeming or nominal disadvantage in respect of range.
Gough Thomas's Gun Book P.160
