I round them a little on my wife's arrows, a natural thing to do with a file. Some of the guys do not. With single bevel heads the tanto tip seems more like a a natural thing to do to meld across the cutting edges. On a double bevel the tanto tip looks to be separate from the line of the cutting edges. The amount of power behind the head will make a difference on how quick they bend as well. The only head that I have ever seen damaged out of 48 deer was a three blade Wasp. One blade stayed in the hide, one in a rib and about half of the third hung on and went through the heart. The deer still went down in 20 yards, but with only a half of a pieces of that copper razor blade intact, lucky for me, it was still enough. That was out of 70 pound Schulz and a 2020 shaft. What a terrible combination, making a Schulz shoot a flimsy Wasp thing a ma jig. I have never seen any other damage with bone contact on any other head. I am sure it happens, just not in my experience.