I happen to be fond of stevens single shots and just being in the woods with one makes me feel good. Yesterday I went to my favorite spot and after two weeks of passing up small bucks my chance finally came. A hot doe with a spikehorn right on her butt came running to within 20' of me and hooked to the right. Not a minute later a nice 8 point came trotting along in their tracks and stopped at 30 yards and looked right at me. All he gave me was a straight frontal shot but with total confidence in my rifle I held 8" above his brisket and squeezed one off. At the shot he ran with his tail down and I could see that his legs were rubbery and 30 yards later he was dead as disco. Now I mention all this because it was done with a cartridge that all of the deer hunting pundits say isn't any good, yeah right. My rifle is a beautiful Stevens 44 that was converted from 32RF to 44/40 by Dennis Olsen in Montana and I don't know what happened when he re-bored it but it shoots M.O.A. all day long.  I'm not a black powder guy but I keep my loads sensible. In this case it's 7.5 grains of Unique with a 215 grain bullet cast at 13.5 BHN. At 1050 f.p.s. it doubles in diameter and 75 yards or less it does a quick and clean job. Not only do I have meat in the freezer but I have the satisfaction of using a timeless rifle.

Congrats on the deer Jonathan! I am a big Stevens fan myself.  I have a Stevens 44 1/2 in .44-40. This rifle was a parts gun that now has an original Stevens full octagon barrel that was re-bored from  .22 long rifle to 44-40. Stevens did chamber  .38-40 and  .44-40 cartridges in model 44's and 44 1/2's, very rare guns in those calibers. I have never seen one.

The 44-40 is not to be laughed at. Then there are the Boer boys in South Africa who had contests on dropping an elephant with a 22 RF. Turns out you can get to the heart with the right thin skinned soft spot on the chest. It also encouraged running contests, too.

As you have already figured out, a big powerful cartridge will never make up for poor shot placement. 
Congratulations