http://www.calguns.net/calgunforum/showthread.php?t=670439 Decided to see what would happen with Hornady Z-max (V-max, TAP-FPD) ammo, after some controversy arose about penetration through drywall using an AR-type rifle. The short version is it penetrated 3 walls, but not 4. Pistol, FMJ ammo, and buckshot all penetrate much more according to other tests I have done and seen. Here's the link to the testing write-up: http://landryreloadingdocs.com/6.html You can mostly ignore the rest of that site. That business is mostly on hold until I can source labels with a better adhesive.