Now I'm working on forming some brass. The "book" diameter of a .44 Henry seems to be .446, which will take some work. Oddly, the used .44 Henry dies (by CH-4D) I have seem to form a slightly bottlenecked case, with a base of .448 and a neck of .440. Not sure what that is about, but it will be interesting to see. In any event, I figure I can form and shorten .44 Russian cases, but I have broken enough dies to know that you run a risk if you try to full-length form a case from .457 (.44 Russian case head diameter) to .446 with regular sizing dies. You need to take special steps when forming the head, and anyone who has heard that telltale "ping" of a die cracking knows what I mean. Fortunately, last summer I made up a series of head swaging dies out of bolts to take .44 Special case heads (.457 diameter) down to form .44 Merwin, Hulbert cases (which are a straight case of .440 diameter), so if I poke around through what I've got already, I may have what I need.
Of course with every "fortunately" there is usually an accompanying "unfortunately," and today is no exception--it seems this rifle was dry-fired enough that the rimfire firing pins made dents in the end of the chamber--they're actually pretty small, but they have raised corresponding burrs on each side of chamber, at 3:00 and 9:00 o'clock that scratch the full size brass more than I'd like. They must be fairly small--only few thousandths tall--because they don't scratch a .440 diameter case, but they are big enough to scratch a full-diameter case and interfere with seating a cartridge of .448 diameter. I suspect they would also put some drag on the case after it is fired, which could be a problem with extraction--1866 extractors are not particularly robust. With the geometry of the barrel and receiver, these will be a little tough to get at, but I am not interested in pulling the barrel out of the frame, so we are in a delay mode for a little bit while I hunt down my bent Swiss riffler files to see if I have something suitable to use.
Below are photos of the chamber burrs and the partially formed .44 Russian cases. The burrs show as two little shiny areas at 9:00 and 3:00 o'clock. The case shows several scratches, because I ran it into the chamber a few times to find the location of the burrs. You can see that each scratch starts about a third of the way down the case, which is about the bottom of the very very slight bottleneck formed by the dies.
--DJ