I used # 8 or # 10 gauge bare wire. I heated and annealed it, but don't think you need to do that. Ever so slightly chamfer the MC, and chamfer the wood next to the barrel. Yo udon't need a huge head on the rivet. Cut it just slightly longer than you need. Then your hard center punch in the middle of the wire to start the copper to flaring outwards. Then hammer it until it fills the chamfer, and stop, or else you'll create a dimple in the MC. Now you can file it flush on both sides. A dab of thin super glue on the wood side will help hold it too.