I had some straight edged four blade and some concave ones when I was a kid. I shot a deer with one of the concave jobs. Supposedly they could be screwed onto a wood shaft without glue. I could never get them straight when I tried it.
One time, when I was 14 or 15, I was testing them by shooting an expired Herters catalog propped up with a stick stuck in a hole a drilled into it with my neighbors drill press. I stuck the first one in at about 15 yards and then took a few steps back. The first hit slopped it back a bit, but it was still standing. The second arrow with the four blade Hilbre skipped off the Herters catalog went up and over the high lines that ran down the alley. The mean old lady across the block that chased me with a garden rake, when Hansy shot her in the butt with a slingshot, was just going into her house. I almost yelled out but I could see that the arrow was either going to stick on top of her house or short of it and to her north a few feet. HOwever, it hit the cross bar of her clothes line and slammed into her white aluminum door about three inches below the glass right as she was closing the door. She opened and closed the door three times, looked around to see what made the noise before she saw the arrow stuck in the door right about at the height of her head. Then she freaked out thinking that I was trying to get even for when she mistakenly tried to kill me with her garden rake. I explained what happened and she was so relieved that it was just an accident that she made no further trouble over it. The only problem was she did not want me to fix it and I had to look at that four blade hole in her door till after she died and someone else owned the house. The broadhead did not bend from all of its wayward travels that day.