How do they hunt? Ground hunting doesn't give good trails in my experience, because the holes are even and higher on the body so the chest cavity must fill with blood before it comes out.
Conversely shooting from elevation give a high hole and a low hole, the lower hole bleeds much sooner if not immediately.
This is essentially the same thought I had just reading the thread title.
Two recent experiences:
1. 2023 early January, .50 flintlock, PRB, 25 yards on a big button buck. Slight quarter-away angle. Tree stand, about 15 feet to my barrel. Ball entered perfectly behind the near shoulder, knocking the deer to the ground, it thrashed around, got up and ran the way it had come. I waited 15 minutes before getting down, walked to the house, waited another 30 minutes before returning to track.
Hardly any blood at the point of impact, very little more than specks on the tracks going into thick brush. After about every 15 or so feet there would be a light spray of blood on the left side of the tracks. No exit hole. Eventually after about 60 yards a pool of blood where the deer stopped... he then trailed off to the right about 15 more yards where I found him.
The ball took hit both lungs and lodged in the off-side shoulder under the skin. The ball expanded to .586 inches from the .490 and had two grains weight loss. Blood trail... an issue of high angle entry, no exit. It took a good 50-60 yards for the chest cavity to fill enough that he was putting out decent blood. The light spray was his exhaling and looked as if someone with a bottle of Windex was squeezing off a burst every 15 feet.
2. 2024 early January. .50 flintlock, Powerbelt, 35 yards on a mature doe. My friend was in a tree stand behind my house, about 16 or so feet high at the barrel. The doe was in front of a trail cam when he shot so we had an excellent view of the bullet path after the fact. At the shot, he thought he missed as she turned and bounded away. No blood at the point of impact. A few hairs and nothing more. We made it about to 20 yards to find blood and it wasn't much, trickles mostly on brush she passed by, very little on the ground. I would estimate that she made it nearly 100 yards before piling up. The blood was never heavy at any time, again, mostly where she rubbed on saplings. Obviously that, in my opinion, god-awful powerbelt never expanded. On skinning her, a .50 pencil hole in and out and even at the lower third body exit hole, very little blood had come out with all her running and leaping.
I will personally stick with PRB and continue to harass him to use anything but those hard nosed powerbelts on whitetails.
** going to edit/add...
I shot a life-time buck in 2023, crossbow at about 35 yards. Heart shot. No blood on the ground just on the bolt. I knew I hit him, you know the sound. I watched him run/leap about 50 yards weaving through brush and then heard him fall and thrash. I knew he was dead. Essentially no blood trail. The last few yards, blood every where, pools of it. Perfect hole through the middle of the heart, which is lower than I aimed as I always prefer double-lung to anything if possible. Since we're talking implements and such, just another data point.