Gentlemen: Although I am flattered to know that I may have some folks fooled, I claim no expertise on barrel and choke boring other than personal experience; therefore I can only regurgitate what others I consider pros have shared with me. Based on my discussions with a double gunsmith who's opinion I highly regard, I tend to agree with Mark that vintage gun barrels were bored to perform with the shell technology of the day. I suspect that early wad technology had a great deal to do with degree of choke, as powder gas blow-by allowed by the fibre wads used in that area would certainly create erratic patterns. Certainly these early makers determined the most preferable degree of barrel choke constriction, as well as the point at which further constriction was counter productuve, thru many hours of experimentation and patterning. Additionally, period technology had not perfected ways to minimize shot deformation; another contributor to erratic patterning. Given these limitatins, what we now consider "extra choking" was "just necessary" to creat a 70% full-choke pattern at 40 yards. When period ammunition is contrasted to modern high-quality loads, there are a number of important differences; but it seems to me that the major difference is in wad technology. The base of a modern shotcup is designed to instantly expand upon firing and will completely seal the bore to protect the shot column from powder gas blow-by; early fibre wads were compressed on firing and therefore were made oversized to compensate. Fibre wads can also be pushed sideways in a bore, something impossible for a modern wad/shotcup, another problem factor that often created havoc during early shell development; and further, fibre wads have the potential to occassionally lodge (in varying quanities and at any angle) inside a barrel tube with the unfortunate result of a buldge or burst if the shooter failed to notice the obstruction. (After witnessing a barrel burst from a stuck fibre wad, which are more apt to separate from the shell base and become lodged; and what it did to the shooters hand, I made it a practice to always examine my bores before reloading when shooting shells with fibre wads). Modern shot cups also cushion the shot charge to a much greater degree than did fibre wads, thus minimizing shot deformation (which can be even further reduced nowadays with plastic fillers and harder/rounder shot). Given these major improvements, improved gas seals and rounder shot, it is little wonder why it takes less constriction today to get full-choke performance and overall better pattern performance for todays shooters throughout the entire choke spectrums. My personal position on chokes for vintage guns, after many years of shooting them, is that a shooter should use a gun choked either up or down to his shooting ability. In most of the south (which is my home), full choked guns are about as useless as tits on a boar hog for anything but head shots on a turkey and trap shooters; so the vast majority of shooters use improved cylinder for shots in thick cover and modified chokes for dove shooting. In the past I have opened many vintage gun chokes to improved cylinder/modified and even skeet/improved cylinder; all performed extremely well, so a shooter gun with chokes altered by a qualified gunsmith don't bother me one whit. On the other hand, if a guy is a purist and would be distressed at the very thought of altering a vintage choke, then he should use something equivalent to the Spred-R load by Polywad. These shells have performed well for me on clays and perserve quail, but I personally do not like them for truly wild game birds (wound more birds than is acceptable to me). Sometimes we collectors get bogged down in meaningless details, and although understanding the whys and wherefores of vintage choke and choking is great information to know; the most important point to remember is that these old guns were originally manufactured (and choked) by their makers to be very effectively used. Therefore, if we are to use them effectively, and consistently, a gun must first reasonably fit a shooters style; and secondly, have barrels choked to the degree at which a shooter can use it most effectively (not over-choked for his skill level). In my experience, with the exception of those shooters who regularly shoot trap, few shooters can consistently perform well with a full choke. To the average shooter, nothing is more discouraging than missing; and a more forgiving choke can do absolute wonders to build a nimrod's confidence! Just my thoughts, Tom