I found this in a bunch of stuff, can’t seem to figure out what it is. Lead flat tip bullet, brass case, copper primer.
Bullet Diameter: 10.74mm (.423). Case Mouth Diameter: 11.61mm (.457). Head Diameter: 11.90mm (.4685). Rim Diameter: 11.90mm (.4685). Case Length: 37.11mm (1.461). Overall Length: 51.48mm (2.027).