I'm of the opinion that muzzle energy, at least with handguns, isn't a good way to determine how well it will work. Simple reason is that often times a deer might take off after being hit with a rifle that produces much more energy.
There is a certain amount of energy needed yes, but people over think this too much. To the OP, without hesitation I would (and do) choose the .45 Colt. It's well known that a big ole 250gr hardcast will shoot through a deer from one end to the other (at 100yds) even at 900-950 fps muzzle velocity. So even though that only equates to 450-500 ft-lbs of muzzle energy, it clearly has enough to take any deer with ease.
So what does that tell me? It tells me that energy isn't the be all end all factor. Punch a .45 cal hole all the way through a deer and you've got a dead deer. Now I load a 250gr XTP to 1400 fps in my Ruger 5.5" Bisley. That's 1,088 ft-lbs. One good big game load is a 330gr hardcast that will leave my 5.5" Bisley doing almost 1,300 fps, which is over 1,200 ft-lbs.
But even still, those energy numbers are less than a 30-30, but I'm also shooting a bigger, heavier bullet than the .30-30 and my handgun loads are also going to out penetrate a .30-30. See, big bore handguns do one thing very well, they cut big holes and dig in deep. And actually, they out penetrate many magnum class rifle cartridges! Big, heavy bullets just flat out penetrate.
.357 Mag is a solid choice and plenty good for deer, but the .45 Colt is more potent. You don't have to drive a big bullet fast because it's got momentum on it's side, but with the .45 Colt you can drive them fast if you want. Even service class pistols like .40's and .45's have no issue dropping deer, which goes to further my point that it's not energy so much as it is penetration (and shot placement of course). And bigger bullets cut wider wound channels.
Glocks and Single Actions
Last edited by Ruger45LC; June 19, 2013 at 07:15 AM.