The little H&R singles were made for the .44-40 shot shell which wild west performers used in their acts so as not to have bullets landing all over the countryside. Later the .44-40 shot was expanded with a paper extension as the .44XL. Meanwhile the shotshell we know as the .410-bore was evolving from the European 12mm shotshell, and soon the guns were being chambered to handle either shell for a few years prior to WW-I. In reality the .44 caliber shot guns are pretty overbore for the .410-bore shell. The .410-bore spade for my bore mic just rattles around in my .44 SHOT H&R.
I doubt anyone knows how many were made, and I don't think the shells, either .44-40 Shot or .44XL Shot survived WW-II. The .44XL Shot was still offered in my 1941 Stoegers, but is listed as discontinued in the 1948. Over 40 years ago we got a part box of Peters .44XL Shot cartridges loaded with semi-smokeless powder. My Father and I aggreed that nothing on this earth smelled as bad as shooting a few of those shells!! They would take a Crow off the bird feeder from the back porch, but the much quieter and less smelly pellet gun was to be preferred.
