I'd figure that a .38-40 in cowboy loading would be a bit lightweight for performance, except maybe a close-up neck shot.
It wasn't a cowboy load. It was a standard .38-40 load, a 180 grain soft nosed jacketed bullet. I know that the .38-40 is not a powerful round. I had three does feeding out in front of me. I waited until I had a 40 yard standing broadside shot. The stand I was in had a shooting rail so I had a braced shot. I know I hit the deer where I was aiming (in the heart lung area.) The deer ran off bleeding heavily. My friend and I trailed it for over 500 yards before we lost the blood trail in a area that was so thick and had so many vines and briers and brush that you couldn't even walk through it. We hunted for over two hours but could not find the deer. We were amazed that it could go that far bleeding so heavily.
(Luke 11:21 KJV) When a strong man armed keepeth his palace, his goods are in peace:
(Luke 22:36 KJV) Then said he unto them, But now, he that hath a purse, let him take it, and likewise his scrip: and he that hath no sword, let him sell his garment, and buy one.