10x63.5 R Sharps Straight "WRA 40-70 s.s.", no projectile

This appears to be called “10x63.5 R Sharps Straight”. Mine had no projectile but about a third down had a ball of cotton which I mistook for a spider or some insect web, even though it looked dense (so am I at 11pm after a day at a gun show). Thinking that s.s. stands for shot shell, I poked the cotton ball, and not finding a spider, pulled it. After that came white powder and at the bottom above the primer sat a bunch of large black crystals (you can see some in the white powder). So, what’s going on here? Did someone convert a rifle cartridge into a shotshell without a projectile? Or someone just pulled the bullet and left gun powder inside?

Gun powder, especially early smokeless types, comes in many colors?

With smokeless powder the cotton wad was used to fullfill the large case, since with black powder the charge fullfilled the case to the base of the bullet.

S.S. stands for Sharps Straight

Back when this cartridge was made, the ammunition factories were also loading rifle rounds with wooden sabots which were hollow and loaded with various sizes of small shot. It is a common thing for a cartridge of this age to have a cracked sabot which caused the sabot to come out of the case. So, this may have happened to the one you found, M. Rea

That would tally with the amount of powder which would be about right for a shotgun type load. The black crystals could be a small amount of black powder in the bottom to act as an accelerator. Try putting a match to one of the crystals the smell will let you know if its black powder but don’t do it in your hotel room unless you want to set off the smoke alarms and get thrown out.