Most effective factory load - 460 S & W ?

Ruger made a Ruger Number 1 Medium Sporter in .460, but it was discontinued for 2013. I know of no factory .460 rifles currently in production. You can get a custom built, but I think it'd have to be either a single shot or a lever gun, and you'd have to watch which platrorm you used because of the pressure that the .460 develops. IIRC Wild West Guns (Alaska) makes custom lever guns and they might be able to make you one.

.023 difference in bullet diameter.

There is little a 460 can do that a 44 cant do. I would not invest the money in a 460 just because you had a deer run 150 yards after being shot with a 44.

Buy one if you want one ...... but it aint gonna kill a deer any deader or more reliably than the 44.

What happens if you hit one with a 460 that runs 150 yards?

I missed a part of the original question .... what is the best factory option available. If that is meant to ask what is the best factory option available to anchor a deer right where he stands I would have to go with a 12g shotgun.

As subtle as a sledge hammer but few rounds are as devastating at ranges under 100 yards than a 12g slug.

My bad, at first read I took it to mean is the .460 the best performing CF factory round for deer hunting in Indiana.

Looking at the question a different way, I'd say the answer is "the most accurate weapon that you can shoot". If you don't want to track deer after the shot, then get one that is gnats azz accurate and either head/neck shoot 'em or shoot them in the spine with a high shoulder shot. They drop in their tracks when hit in those places.

For the past few years I've been using my Savage Muzzleloader. I rebarreled it to .45 cal, and I shoot the 195g Barnes .40 cal bullet pushed by a healthy dose of H-4198. MV is 2850 fps with that bullet, and I shoot 1/2 moa groups at 100 yds. Sighted in at 200 yds, it's 2" high at 100, 9" low at 300 and if you want to run it out to 400 yds, it drops 27" out there. Still has 1200 fpe at that distance too. 2 years ago I shot a doe at 20 yds that was facing me. (I was on the ground). I put the crosshairs where the bottom of her neck joined her chest and squeezed. Her legs folded up and she went down so fast that she didn't even roll on her side. I'd be looking at an Indiana legal CF deer rifle if I didn't have that Savage, but if I can't increase the performance, why should I spend the $$? From the muzzle to 250 yds it only rises 2 1/16" and drops 3.5" so I just hold right on the middle of the deer and squeeze the trigger. If it looks like it's past 200 yds I'll break out the rangefinder, but inside that there is no need for one.

I've concluded that if you shoot deer through the lungs or the heart, as most of us do, they will run a little ways no matter what you shoot them with.
My cartridge of choice since handguns became legal has been the .44 magnum. I've shot many deer with .44 magnum handguns, and now with .44 magnum rifles. If I shoot them through the heart, nearly all of them will run 75 to 150 yards. They always leave an easy to follow blood trail, and have always been dead when I walk up to them. I used to shoot the 240 grain soft point WW white box ammo, then started using 250 grain Winchester partition gold factory loads, until it became difficult to find. I now use 240 grain Hornady XTP HP's over 20 grains of 2400.
This fall I shot a doe similar to how the OP shot his buck. The shot was 25 yards. The doe kicked then ran into the brush. I gave her about 10 minutes before following the vivid blood trail. She had gone about 75 yards and was done when I walked up on her. The bullet had gone through her heart, plowing a trough across the top of it, then had exited through her off side shoulder. The shoulder was broken, but I didn't notice her favoring it when I watched her run off. Since spine shots and head shots are not something I want to do, I have accepted that deer will simply run, and blood trailing them is part of deer hunting.
As to the S&W 460? I'd think it would be a great deer round too, but I think deer shot with it, as I shoot them with my .44's, would run just as far.

I've seen guys lose deer hit with 358BFG's....

Guys who are what I would consider steady of nerves and good shots.

No such thing as a sure thing.

Last deer that I shot this year was a doe at approx. 80 yards. She was shot Saturday, Jan 4th. .40 cal. 195g Barnes "X" bullet. Impact velocity approximately 2477 fps. Broadside shot, double lung. Shot a bit far back, missed both shoulders, although the bullet was far enough forward that it did not penetrate the diaphram. Exit hole was slightly larger than a $0.50 piece. She ran approx. 100 yds and laid down, spraying blood out of the exit side the whole way. She left an 8" dia puddle of blood in the bed, got up and moved another 20 yds before falling over. I couldn't believe she went that far with that kind of a wound. Just goes to show that not every deer will act the same when hit. She was pretty relaxed when shot; she was with 4 others in the process of moving from a feeding area to a bedding area. They had no clue I was there.

I have had nothing but good luck on deer out of my .357 mag using Leverevolutions..