[edgarspencer]

This box contains many of James P. Hayes personal choke reamers. Most all are stamped with either his name, or his initials, along with the bore (12, 16, 20, etc) and are also stamped with dates between 1895 and 1903.
Without having a set of centers, some are difficult to measure as they are five fluted. This collection was given to a friend by Charley Parker, in addition to many other tools. They have since been passed to me. I also have James Hayes chamber rim cutters (all the way to 8 ga.) and a few chamber reamers.

Looking at the choke reamers, what is evident is that the cutting portion of the flights varies somewhat between 3 3/16" and slightly over 4" (20ga.)
There were no specific reamers for specific final choke diameters; the reamer was simply pushed further into the bore until the desired diameter was achieved. With this collection, I also obtained the rods which the reamers were screwed to. These rods have adjustable stops, which allowed the breach face to only move so far in relation to the reamer. The length of taper, logically, for a full choke was close to the full length of the reamer, however, a choke considerable more open would have a uniformly shorter taper.
I do not believe there is any data which supports the belief that there was a "Standard" length of taper. As reamers required sharpening, they were ground, on offset centers, and, consequently the length of the cutting portion, at a specific diameter, would become shorter over the life of the reamer. These tools were likely the property of the individual tradesman, and they may have seen many regrinding cycles. Today, the reamer would simply get tossed to the scrap barrel, and operator would take a new one out of the tool room.