What are the two or three best artificial media for testing stability of a bullet after impact? By "stability," I refer to a bullet yawing in a different direction from which you aimed it. The best example of instability - that was planned for during development - is the original 5.56 mm military bullet to be fired from an M-16 with 1:12-inch rate of twist. Upon impact with people, the every-which-way that bullet traveled wreaked tremendous damage - but didn't penetrate well. Current 5.56 mm ammunition-rifle unit now penetrates well but is much less effective in terms of destruction on human beings.

You're reading too much and maybe the wrong stuff.

Ballistic gel, like on TV.