James, I bow to your knowledge on this. I just always figured that since some guns I have seen are "shaved" more than others, that it was individual smiths. But having the guns shaved in batches (possibly by different firms?) and at different times would also explain the variations.
I do know that there were at least some unshaved guns and .455 ammo imported and sold back in the 50s, as I have ads for them in old American Rifleman issues.
I did know about the English only issuing 12 rnds at a time. When it comes to ammo for the troops, the Crown has always been ....frugal.
I can also see British officers going into combat with empty revolvers. After all, if they had wasted what the Crown provided for ammo (either in practice or using it to save their own, or someone else's life) they still had a duty to perform. And officers are expected to lead, not fight, anyway....
I believe that an American officer would also do their duty, and would go into combat carrying an empty handgun, if no ammo was available. I also believe that an American officer who did this would be carrying something else, that was loaded, as well. I know I wouldn't hesitate a moment, if I was in that situation. But a British office, a century ago? Quite plausible they might not. Bad form, old chap. Against regulations, don't you know?
Late 19th century militaries were commonly stingy about issuing ammo to their troops, and particularly those with colonial empires. Ammo was valuable, and almost never given to troops in garrison (small amount for guards, only), because of the simple fact that outside of the practice range or actual operations, ammo in the troops hands tended to disappear, since it was one of the few military items that could be sold, or traded for drink, food, or other "recreational" activities.
And since rules are rules, there was a strong tendency to continue to keep bulk ammo under watchful eyes of the quartermasters, even when the troops were in the field. A fairly good, but subtle, example is in the movie ZULU.
While flawed in some ways (most notable is the apparently unavoidable use of more modern arms (SMLEs) to supplement the numbers of Martini's in some scenes),
Zulu does do a good job of showing some of the attitudes and tactics of the times. A lot of it is lost on viewers who don't have an interest or background in the history of the times, but it is there for those who can see it.
A fairly large group of British were overwhelmed and wiped out by the Zulus, primarily because they faced a much larger number of Zulus, in open country, and their officers fought "by the book". At Roarke's Drift, a much smaller number of men were able to hold off the attack, primarily because the officer who wound up in charge was able to both think, and act (in today's parlance) "outside the box". Fortifying and fighting from the station, as well as a complete disregard for the regulations about ammo issuance added greatly to their ability to fight, and ultimately win.