That very question has been the topic of conversation between my son and I for the last week. Last Saturday my son shot at a doe at 45yds standing broadside in a clump of wild sunflowers. The stems on these are about 1/4" dia. He didn't think they would deflect the 300gn bullet so he cut loose. The bullet hit 6" low and sideways, low in the brisket. We eventually got the deer with a followup shot after trailing it over a mile. It doesn't take much we found out to disrupt a bullet. Luckily we hunt in wide open country and could keep up with the deers path of escape.
Zen