RE: Lost a good buck yesterday!
I have a 7mm Mag too, I gut shot a buck once. It got dark fast and I didn't have a flashlight, I went home and brought my dog and a couple of flashlights. When I took the dog to the spot where I estimated I had hit him the dog started tracking towards the woods (where he ran) and stop and sniffed the grass and pulled me in. As I looked where she had sniffed I saw something red on the grass and it was blood. That was the only sign of blood we had until about 50 yards in the think brush where I saw one more spot and we cam out to a small openening in the brush where he was laying in the 'bedded' position.
So there might be very little or no blood trail, even with a rifle.