That's a great shot Fly! I have to say The Thunderheads I've shot have for the most part left good blood trails. This year switched to Slick Tricks. Shoot great, got a buck with them but shot was a little high so of course not going to see a ton of blood till the chest fills up. I had blood but glad I saw where the deer went down or I might have been looking longer. Other factors to consider also is I think of is the muscle, you put a hole through it, the tendency for the muscle might be to close back up a little as, there are layers to some of the muscles and all those muscle fibers, hence impairing blood flow, hair gets shoved in the hole, etc. Ground litter like leaves or pine needles also make it tough to track. I agree though, shot placement has alot to do with the blood you get