Will a 300 Blackout subsonic kill a deer? Of course it will. This deer was shot at a range of 75 yards with a Remington Factory 220 Grain Subsonic Sierra Matchking hollow point. The upper is a AAC 9" barreled coupled with the AAC 7.62SDN-6. This was a standard lung shot, nothing fancy. The bullet impact into the deer was louder than the suppressed gunshot, I could clearly hear the impact and the bullet exiting and whizzing into a tree on the far side of the deer. It went about 40 yards and piled up. Note the blood around where the deer fell. The deer stood in that spot for about 10 seconds.
This is the side the round exited, which appeared to indicate the bullet exited sideways from the animal.
This is the exit wound from the inside; note the oblong shape
This is the entrance wound
This is the entrance side of the lungshot
This is the exit side of the lungshot; note the black areas, as the bullet was undoubtably sideways at this point and creating a nice wound channel...
I have read a lot of posts over the years about the ability of a subsonic round to kill a deer. I have been hunting since I was a small child, and I have killed lots of animals with subsonic ammunition before, but thought I would share this with the world so put the myth to rest. As with all hunting...shot placement is key.