I love black powder guns and air guns. When they are air guns styled like percussion or flintlocks it's great. This pic from elsewhere on the 'net is a pair of Contriner pistols from 1799. They are .40 caliber.
That is a Beautiful pair of pistols for sure, I mostly hunt with air rifles now days, Air Force Texan 45 and XP Airguns Ranger 45 and Badger 40, but I still love shooting my BP 32, 36, 45 and 50s.
Nice pair of pistols for sure. I just wish I could afford one of them and an air rifle to pair it up with. I was surprised to find out air guns has been around for centuries