About this 3D model
Based off of the 7.62x51 NATO Wikipedia's dimensions photo here . If you just want the keychain in the photo, it is ‘752x51_keychain.stl’ Can be used as a keychain with the loop in the bullet, or in the bottom of the casing. You can also use PrusaSlicer to add a cut on the keychain model right where the casing meets the bullet to print them in separate colours as I have in the photo. You can also add connectors to easily attach/detach. Could also print the bullet with a ‘tip’ of another colour like red/black/green for different types. Used the following filaments: Casing: AMOLEN Silk 1.75mm Gold Bullet: AMOLEN Silk 1.75mm Red Copper Want a bigger round? Check out my .50 cal version . Smaller? Try my 5.56/.223 version .