Testing bullets for directional stability

[Naphtali]

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.

[303Guy]

I use rubber grounds. I can't say it's great or bad but it doesn't seem to tip my boolits no matter how slow or long they are. Maybe a 10 twist 303 just isn't going to be unstable.

Crumpled rags might be a better test medium due to irregularities in it. I have used water logged wool furniture padding but that only produced mushrooming without destabilizing anything I shot into it and I shot 55gr bullets fired from a hornet with a 16 twist barrel and 303 cast.

[Hannibal]

I presume you are speaking of bagged rubber mulch? I have had RCBS 35-200s yaw 90 degrees in that stuff. Loaded in .38 special cases and fired from my Henry .357. Not in the loading room or I'd post a photo. It's completely obvious on the bullet what happened, not to mention the key-holes in the cardboard dividers I had in the box. Surprised the heck outta me!