I used the broken handle of a hammer upside down. Wrapped the end with friction tape for a grip and the other end wrapped with a thick rubber tape, then several layers of aluminum tape and then fiberglass tape for heat resistance. Drilled out the end with a 3/8 bit deep enough to tap three .38 special wadcutters in there then poured a bit of molten lead to seal them in. Makes a perfect thumper/sprue plate opener and bullet drop persuader for me.