A pair of men's cuff links made from the spent shell casings of a standard 7.62 military round. The spent rounds were donated by some members of the local base's Security Forces unit who asked for a set in exchange. You could check firing ranges as well for spent shell casings of varying caliber. I already had all the tools and hardware needed so your price may vary if you need to purchase any of them.
These polish to a beautiful shine and can either be allowed to patina or can be coated in a clear varnish to maintain the shine.
Some of the materials you'll need. Ensure your shell casings have been fired! Do NOT use live rounds! A stout pipe cutter can be found at home improvement stores in the plumbing department for under $15. The cuff link blanks are from Hobby Lobby at $2 a pair. Not shown are the flux, solder, sand paper, and torch.
You can substitute a good metal-to-metal glue such as JB Weld or Liquid Nails for the solder if you'd prefer.
Using the pipe cutter, cut off the end of the shell casing. I usually cut off more than in the picture
The thicker cut ends that I normally use. These are a different caliber but they look the same. While the pipe cutter is fairly smooth, I still sand the rough ends just to be sure it lays flat.
Set the shell piece into the cuff link blank and apply flux all around the edge where the two metals meet. Apply solder using a micro torch. I didn't take a picture of the actual soldering as the flame kept doing wonky things to the lens.
Once it cools, check the join to ensure it's not going anywhere then clean the carbon with a soapy scrubby and allow to dry.
If you prefer to use a type of glue instead of flux and solder, apply an industrial metal glue such as JB Weld or Liquid Nails and allow to dry.
Clamp it into a vice with a rubberized surface so it won't mar your cufflinks and, using increasingly finer grit sandpaper, buff out all scratches until it shines.
Apply a clear varnish if you prefer.
Give to your favorite gun enthusiast!