Somebody on here posted to the effect that it probably would be OK to shoot through light stuff just in front of the animal.
A decade ago I was hunting eland in Namibia with a .338 Winchester Magnum and 250-grain Nosler Partitions loaded to 2700+ fps. This might seem like a decent brush-busting load to some people. When I finally got the shot it was at 200 yards, with the bull standing broadside in the open--except for a little thorn-twig about the diameter of my little finger right in front of the shoulder pocket. I knew I couldn't hit that twig with a whole box of shells, so aimed for the top of the heart anyway.
At the shot all three of us (me, the PH and a friend) could see dust fly right where I aimed. The bull ran off behind some nearby brush before I could shoot again, but the PH was so certain of a dead eland he turned and shook my hand.
We waited a minute or two then followed up. When we got around the brush where the eland had run, we were quite surprised to find the bull 100 yards away, still standing. I gave him another through the lungs and he went down.
When we walked up on him there was a perfect silhouette of a 250-grain .338 Partition in the skin, right where I'd aimed. The thorn-twig was had been so close to the bull that we also found little swirls in the hair around the silhouette, where the thorns had whipped against his hide. So in a matter of inches a 250-grain bullet had been turned sideways by a twig.
I have run my own brush-busting tests and couldn't find anything that got through light (1/8" to 1/4") twigs consistently. Oddly enough the best caliber in my test was a .243 Winchester with 105-grain Speer spitzers handloaded to near 3000 fps--because the slim bullets would sometimes find their way through the brush without hitting any of it, unlike the fatter, heavier, blunter, slower bullets that in theory are real brush mowers, including a .358 Winchester with 250-grain roundnoses and a .45-70 with 405-grain flatnoses.
I have also had a variety of super-tough bullet deflected by brush, including 160-grain 7mm Fail Safe and Barnes TSX bullets, and a 168-grain .30 TSX from. They never even touched the animal they were aimed at. In those cases I thought I was shooting through brush thin enough that the bullet could be aimed into a hole, but it didn't work. My conclusion from those experiences, along with the eland, is that bullets often find brush on their own!
