Nice article
https://surplused.com/index.php/202...p-shotgun-designs-part-1-of-3-1833-1889/ The site is Spanish, but appears to show the 16g dimensions
https://municion.org/producto/16-cal-16-gauge-roper-shotshell-short-groove/ ![[Linked Image from photos.smugmug.com]](https://photos.smugmug.com/Shotshells-and-pressures/Shotshells/i-39WLMv2/0/71efa3e8/S/Screenshot%20%28834%29-S.png)
https://forum.cartridgecollectors.org/t/listing-of-shotshells-calibers/1562/29?page=2Roper produced shotguns and rifles. The shotguns were in 12 and 16 gauge; these were usually only offered with smooth bore barrels. However, some of their shotguns were sold with a rifled barrel insert and replacement cylinder, which obviously reduced the size of the bore to some other caliber, probably for use with their .41 caliber cartridges. The Roper rifles were produced in .41 caliber; these had rifled barrels, but could be had with a second barrel with a smooth bore. The early Roper shells and cartridges used percussion caps; the later ones were Berdan primed.
Scroll down to lot #204 - a 20g 2.43" Roper steel shotshell
https://www.proxibid.com/asp/CatalogPrint.asp?aid=146127A Roper cartridge
https://www.gunboards.com/threads/unusual-cartridge.1181965/ Wow
https://www.rockislandauction.com/detail/50/1105/rare-cased-roper-revolving-shotgun-with-accessories
