Bullet Shell Valve Stem Caps
![IMG_5790.JPG](/proxy/?url=https://content.instructables.com/FUT/4FN1/GOWNTHOU/FUT4FN1GOWNTHOU.jpg&filename=IMG_5790.JPG)
![IMG_5795.JPG](/proxy/?url=https://content.instructables.com/FSM/NM76/GOWNTHOX/FSMNM76GOWNTHOX.jpg&filename=IMG_5795.JPG)
![IMG_5793.JPG](/proxy/?url=https://content.instructables.com/FYV/3W9M/GOWNTHOV/FYV3W9MGOWNTHOV.jpg&filename=IMG_5793.JPG)
![IMG_5794.JPG](/proxy/?url=https://content.instructables.com/FNV/FC4B/GOWNTHOW/FNVFC4BGOWNTHOW.jpg&filename=IMG_5794.JPG)
The inner diameter of a 40 cal. bullet shell happens to fit nicely over a valve stem cap. All you have to do tap the shell onto the cap with a hammer. These went to the same friend who got the retractable bullet pen.
Safety first: The shells were already expended by the time I got them. Never attempt to use a live round for any kind of project. Serious injury or death can occur.