[ame="http://youtu.be/Z3ka8mvH_xE"]Barnes video link[/ame] 10mm Buffalo Bore 155 gr TAC XP fired from 4.5" barrel EAA Witness through four layers of denim into calibrated gelatin. BB: 600.5 fps, 3.5" Impact velocity: 1,376 fps Penetration: ~14" Retained weight: 154.4 gr Max expansion: 0.696" Min expansion: 0.514" If you look closely, you'll see a bee land on the denim just before the shot and you can see the bullet exit the top of the second block and roll back toward the chronograph. That's why the penetration figure is approximate. I saw the bullet drop to the ground when I shot but I thought it had bounced off the second block until I reviewed the video. [ame="http://youtu.be/IWK551Nd9og"]Mihec cast bullet video link[/ame] 10mm 195 gr Mihec (shallow pin) 20:1 lead/tin loaded over 9.6gr Blue Dot fired from 4.25" barrel S&W 1076 through four layers of denim into calibrated gelatin. BB: 600.5 fps, 3.5" Impact velocity: 1,026 fps Penetration: 23.1" Retained weight: 196.0 gr Max expansion: 0.423" Min expansion: 0.407"