does this Union Metallic Cartridge look familiar?

[Gimmie The Loot]

Found this cartridge the other day in a somewhat new park... can anyone ID this? I understrand it is from the UMC (Union Metallic Cartridge Co) but I don't know how old this slug could be. Any help is appreciated!

[Old Town]

At the turn of the 19th century there were many rimfire handgun cartridges bigger than the common .22 rimfire we are all familiar with.

It looks like you have a .44 caliber round. I think it might even be a blackpowder round as this low pressure rimfire cartridge was still made in BP up until the 1920s. Smokeless had taken over by 1900 but there were many old revolvers that could not take the fast pressure spike of modern nitro. So the BP rounds for these old rimfire revolvers continued to be made well into the 20th century.

I think you have a 1920s era BP rimfire revolver round. They were also made for .32, .38 and .44. No .45 caliber rimfires. You can tell your cartridge is for revolvers by the pronounced rim plus the fact no auto pistol above .22 was ever made for rimfire rounds. The U on the bottom for Union was a fairly modern addition in their line of ammo. It's surely not 19th century but early 20th.

Old Town