[Shop-talk] do we have any metal guys here of high caliber? (shop related)

[Randall]

I'm certainly no expert, but I believe the trick is to angle the steel so the bullets only hit a glancing blow.  Basically a steep
funnel, that directs the flying bullets into kind of a dust trap arrangement where they eventually lose all their energy and fall to
the bottom.  Or put some sort of absorbing medium in the bottom, like sand or mulch.

Google for "bullet trap diy", you'll find lots of designs.  Here's one
http://www.hipointfirearmsforums.com/forum/f277/making-your-own-bullet-trap-295357/

For higher caliber, you probably need to make the angles steeper rather than just making the steel heavier.

-- Randall