I had to dig through my references to find range data for ACW cannon -- average is about 1,600 yards, so it's no big surprise it was punching through walls at 700.
What I'm wondering about is: Could they not have done the test-firing at the old dead airport on Alameda Island (look it up Google maps)? The facility's a mile across to start with; and it's another mile or so to the shipping lanes; so unless they've managed to build a modern-era artillery piece, they're unlikely to hit anything important out there.
Finally: Ever since Hyneman and Savage took over the "executive producer" role, they've actually reduced the Gratuitous Explosions and other non-scientific stuff; so folks complaining about that either haven't watched in a couple years, or (to quote Captain Kaff Tagon) are smoking butt-crack.
