Just an Odd Thought...
 

How far would you have drop an average home safe with average stuff in it in order to penetrate the top armor of an M1 or Challenger?

Do you have a copy of Guns, Guns, Guns Paul? It has all the conversion tables in it for 2nd ed, shouldn't be too hard to crunch some numbers. Calculations with 3G basically come down to the specific gravity of the projectile material, the projectile diameter and its velocity.

LMAO... reminds me of when I played Car Wars and the citizens dropped a toilet from the roof onto a passing marauder van...

Closest we came to that was dropping mortar rounds down onto vehicles and troops from the top of a very tall building after we primed them by hitting them on a metal plate after we had removed the safety pins like Beauford Anderson did on Okinawa.

Worked like a charm.

What is an "average home safe"? Most of the guys that I know there small safe or starter weighs more than a ton, I think about 2600lbs is the average for there "small" ones.

So could a 600 pound steel cube penetrate the top armor of an Abrams? It might stop a M113. for the Abrams the question is how is it hitting flat, edge on or one of the corners?

I would also fill the safe with the heaviest stuff I can afford to loose to boot.

Do we have the option of dropping it from High Orbit? Its the only way to be sure.

One thing it would probably really screw up for sure is the gun if it hit that. Thats a pretty good impact on the tube and not sure it would stand up to an impact of that kind. So you may not be able to penetrate the top armor but she isnt worth much if you screw up the tube.

..an 80lbs load of concrete should do the job dropped from orbit. and no environmental impact statements to fill out.