i milled out some cubes from scrap steel for shooting at sheetmetal. This is just too much fun. From less than 5 paces they go right through a thin file cabinet. Im using two layers of TBG in my W frame. So far I made. 500 inch, .750 inch (my favorite), and some 1 inch cubes, too--but they weigh a quarter pound each I thought maybe the edges were getting dull, because they penetrated better at first, but now I think it was just my target getting work hardened from all the hits Beat up file cabinets I can get free and recycle after, so its all win.