This is my first go at any kind of jewelry. It will end up being a wedding gift for my fiancé. It has been a fun project to see come together.
You may start with a bullet that is meant to be loaded or you can remove one from a live round. I removed mine from a live Russian 7.62x54R round from my Mosin Nagant. You can use what ever round you desire. The best and safest way to remove a bullet from the brass is by far a bullet puller. I tend to do things the hard way so I used a copper tube cutter. I do not recommend this do to the hazards working around live gun powered. Spend the money I didn't and buy a puller. Once I cut open the brass I punched the bullet out on a vise.
You can now take one of your spent rounds and first drill out the primer making sure the hole stays in the center. I used a 1/4" drill bit. Counter sink the hole to add a nice clean taper. Drill one more hole through the side near the primer to feed the chain through. The size will depend on how big your chain will be.