Years ago I read a test that someone did where they set up a "brush box" with several 1" wooden dowels, to simulate shooting through brush. The 1" dowels allowed consistency and easy replacement. He then tried a bunch of different calibers - traditional "brush busters" and high velocity "open country" cartridges.
The fast moving high speed rounds actually didn't deflect much, but the bullets turned sideways. The "brush busters" had the bullet stay straight, but deflect. The end conclusion was, don't try shooting through brush
The one mule deer I managed to kill in California, was lying in some tall grass, looking at me when I fired at his neck. The 150gr, launched out of a .308, clipped some grass, turned sideways, but still hit his adams apple and anchored him.
