Having taken a couple dozen elk over the last 28 years (out of 38 years of hunting), ranging from cows, spikers, and bulls up to 7x7,and having guided friends or clients to several more, I have seen on-game results from various bullets out of the 6.5x55 (140 gr) up to the 376 Steyr (260 gr), from 5 yards out to 475, including several with the 300 Win Mag/WSM. My own bulls with the 300 WSM have been with the 180 gr AccuBond at distances of 70 to 242 yards.
Most of the bullets you asked about were represented, except the ELD-X, and others suggested/recommended by others responding to this thread. I have used the ELD-X on a moose, once, and a Berger on a caribou, once. Both experiences, which did result in one-shot kills, but did not impress due to the bullet expansion and penetration on each animal, or required tracking distance before the animal expired (caribou of over 400 yards) that would make me hesitate to ever use these frangible bullets on an elk. But this is just my limited experience with these, and opinion. Take it for what it is worth! LOL
The elk taken with the 300 mags were using Nosler 180 gr Partitions and AccuBonds for the most part, and Winchester Power Points. Not all were one shot kills or DRT, depending on bullet placement, or the state of the elk at the time of the shot (rut crazed bulls, to wary animals, to unwary animals busy feeding. This has a greater impact on how the elk will react to the bullet impact than most realize or consider.) Some were complete pass throughs, and on others, bullets were recovered from within the vitals or under the hide on the far side. Most were taken with 1 to 3 shots. On elk, I like a follow up shot for insurance (and it is cheap insurance!), especially if they fall immediately, and it is unknown if the shot clipped the spine and only stunned the animal. A wounded elk can cover a lot of country in a hurry, and require extensive tracking for a follow up shot, if you get one! I have seen elk lost; it is no fun for anyone involved!)
If one can be assured to not encounter the heavy shoulder bone (elk have the densest bone of any animal in North America), or that the shot will not have to penetrate through a full paunch to reach the vitals, most bullets will work fine, on a bullet accurately placed in the vitals on a broadside or quartering away presentation. While this can and does happen, mostly it is due to a hunter with the patience and ability to wait for that perfect shot opportunity, and accurately place their bullet in the vitals accordingly.
Many, if not most, shot opportunities are not this scenario.
In many cases, the bull comes running into the call and present frontal or quartering to shots, where more muscle and heavy bone must be penetrated to get to the vitals. Or the bull is at a distance only presents a hard quartering away shot, that requires a bullet that is placed less than perfectly, must penetrate a grass-filled paunch to get to the vitals. In these scenarios, or any other, where the bullet must penetrate further, it must be of stout enough construction to do so, and have the sectional density (min. of .250, with number approaching .300 better) while retaining enough energy to reach and destroy the vitals to provide a clean kill. The 300 Win/Mag/WSM with a 180 gr bullet will typically provide this when it retains 2000 ft lbs of energy at the animal. Factory 300 Mag ammunition with 180 gr bullets will do this out of the typical rifle barrel (24") out to about 400 yards. Many of today's writers say that 1500 ft lbs of retained energy is sufficient for elk. I believe this is due to the mono metal bullet design of many newer bullets than wasn't available back in the day (but in my experience, I still prefer the 2000 ft lb rating, as I believe it provides a margin of safety that provides better on-game performance). This will push the envelope beyond 500 yards.
The key here is the shooter's ability to accurately place that bullet at that distance.
And use enough gun, with a bullet stout enough to work, when things go other than as planned!
All sorts of circumstances can, and do, occur. A twig that wasn't noticed as you aimed, the animal takes a step as you shoot, or spooks because of a shift in the wind, etc.
Err on the side of caution. Hope for the best, but plan for the worst. bullet and ammo.
I should add another bullet not mentioned in the thread above: the Federal Terminal Ascent.
For the 300 Win Mag and WSM, they offer the 200 gr TA. It is a bonded bullet design, with a heat resistant tip for high BC and expansion characteristics. It has a BC of 0.608 and a SD of 0.301. This ammo is rated at 2810 fps and produced 2814 fps from my rifle's 23.5" barrel, and retains 2147 fps and 2046 ft lbs of energy as chronied at 10 degrees C in my rifle. It drops 40.7" at 500 yards given a 200 yard zero.
While I have not used it on an elk as yet, I have been impressed with its on-game performance to date for red stag, caribou, fallow buck, and Arapawa rams in other calibers, ranging from 43 yards to 296 yards. All one shot kills, with the animal travelling the farthest being the fallow buck that jumped and fell down the hillside, stopping 15 yards below where it had been standing when shot. I haven't recovered a bullet yet, as they all passed through, despite encountering heavy bone on some. I would not hesitate to use this bullet/ammo on elk.
Best of luck in your quest!
Elk hunting in the rut is one of the most exciting things you'll ever get to experience!