He is!Your T-Net Profile page doesn't tell your location, but in one of your posts you said you are digging in Germany. That gives me some certainty that your bullet's correct identity is a Hanovarian pattern of German/Austrian bullet, made for use in blackpowder pistols and rifle-muskets.
As Tedyoh indicated, we need measurements in 1/100th-of-an-inch (or fractions of a millimeter) to ID your Hanovarian bullet's caliber.