So...is there a performance advantage over the .338 RUM and.340 Wby? I understand your point about a .338 Win having enough power for an elk, ammo availability, and cost. However my concern is neither of these. I am purely looking for the best caliber.

Absolutely not.The 338ultra mag offers the best ballistics followed by the 340weatherby and the 338win magfollows both of these two.

Good luck. There absolutely is no best caliber. Not for elk or anything else. You need a rifle with enough power to do the job. The rifle is not going to do it by its self. Its what you do with what you have that will determin your success or failure. Every caliber has its strong points and weak points. If you are a good hunter carring anything from the 270 on up, you will be successful. The best will be argued forever, with guns, with cars and even girls. This will always come down to a matter of opinion. Therefore when it comes down to it you will have to make the choice and then live with it. You have some good advise here. Now do your homework and pick one. I have never missed an oppertunity with the 30-06 and 270 class rifles. That is because of the way I hunt and not what I used to kill the animal with.

This is why I would pick the .338 Winchester magnum over the Remington ultra magnum or the Weatherby magnum.

The .338 Winchester magnum is available in about two dozen different factory rifles, while the Weatherby and the Remington ultra are only available in a handful of pretty expensive rifles.

The .338 Winchester magnum also has a huge following in the elk hunting community, and there are many many many great elk hunting loads available in this caliber. There are nosler partitions, bear claws, fail safes, barnes x, grand slams, A frames, and a huge list of other bullets available to choose from when sighting your gun in. What if the two or three elk loads available didn't shoot well through your Remington ultra mag?

You will never meet a man alive that wouldn't list the .338 Winchester magnum as ideal for elk, moose, big bears, or almost any other big game for that matter. It is a time tested and field proven big game cartridge.

Now that you asked my opinion, and I won't get kicked in the nuts for giving it LOL, I am happy to share this information with you.

To go one step further, the 338 Win Mag is even available in one of the nicest semi auto rifles ever made, the Browning BAR!

If you have any other questions, please let me know!

JamesB, not trying to be argumentative but when given a choice of three there will always be a first place and last place.Note my questionwas about performance.I've found my answer but was curious why tom felt so strong about his .338 win. My prediction of his answer was correct.
Anyways group think and popular opinion doesn't merit much in the way of substance. It all boils down to the numbers.

Thanks for your help gentlemen.

The 338 RUM has the best ballistics hands down but at a price. I fired a 338 RUM "3 shots" and the recoil wasabsurd.The guy that fired it before mehunts witha 300WSMand he shot the 338RUM one time, and let a few expletives fly and did not shoot again. All we heard the next morning was how his shoulder hurt. I can only speak for myself but I would be afraid of that gun after a range session. I have also shot a 300 RUM and it was manageable compared to the 338. It is hard to believe how different the 338 recoilwas from the 300.

To be honest ,I own two 300ultramags,have fireda few others, have fired a couple of 338ultramags and have owned a 338x8mmremmag.I found that the felt recoil varied greatly from gun to gun even in the same chambering.My own 300ultramags have mcmillan stocks,decellerator recoil pads and heavier contour barrels and they produce noticeably less recoil than the factory remington 700s in 300ultramagthat I have fired.My 338x8mmremmagwas ballistically slightly behind the 338ultramag,but it also was noticeablyeasier to shoot than the factory 700s in338ultramag.I liked my 300ultramags so much that I sold my 338x8mmremmag.Usinga180grbullet the 300ultramag will shoot flatter than the 338ultramag and it is very effective at killing elk at longer distances.I have now killed 10 elk and 2 moose withmy 300ultramags and not one animalcovered 50 yards after being hit.My shot distances were from 80 yards to 377 yards with mostbeing 200yards to 300 yards.Using the 180gr tsx I would not hesitate to use the 300ultramag on any game in North America.

A first and second place in Who's mind. Like I said it will always come down to one person or anothers personel opinion. There is more to being a good hunter than the numbers. In fact they may have the least to do with success than any other factor. I have guided a lot of hunters who had the nunbers but not much else.Find 20 expierenced elk hunters and ask them what the best caliber is. You will probably get at least 10 different answers. I would agree with Stubble in that a 300 Mag may be the best choice when it comes to everything concerned. They shoot flatter than most of the bigger mags and have all the ME needed to take elk. With that I will leave it up to the rest of you to hash it out. Good Luck to all this season.

I have a .340 Wby. Mag. that pushes a 250 gr. Barnes XFB 3,062 f/s 5,204 ft/lb. I have not found any .338RUM or data faster yet. Good luck.