A fired cartridge case and a fired bullet. The firing pin and breech face impressions on the primer of the cartridge case can be used to identify the gun the weapon used, as can rifling impressions on the side of the bullet.
Firearms - Guides - Importation & Verification of Firearms - Gun
modelo 3d Caja de cartucho y bala - TurboSquid 1399116
Modern Cartridge Case Manufacturing Methods -The Firearm Blog
Unidentified cartridge case and bullet - General Ammunition Discussion - International Ammunition Association Web Forum
Ballain - BALLISTICS - It is a science of the motion, launching, flight and movement of the - Studocu
On a rifle cartridge, why are the case mouth and neck on the
Cartridge, Types, Calibers, Ballistics
Standard Bullets and Cartridge Cases
Cartridge case terminology and identification – Stephen Taylor, WW2 Relic Hunter