Not saying a 25-06 won't work for elk, but I would be concerned about it being on the light side of advisable. I've been in the process of doing load development for a 25-05 and have focused on the Berger 115's. I want to use the Bergers as I want the higher B.C. to flatten the tragectory if possible. I'm pretty close, but need some better weather to check out some more loads. I'm looking at this primarily being a deer and antelope gun.
I've also played with some Sierra Game Kings and some Hornady SST's. Both of these bullets shoot well and I would use either of them if the Bergers didn't work. I would use the Barnes, but I would like a little heavier bullet than the TTSX offers and would probably be just a TSX bullet. I haven't done anything with the Barnes as I didn't track down any bullets. You need to look at barrel twist to see if you have enough twist to stabilize the longer bullets.
All this assumes that you are loading your own. If you aren't, you will need to try several different ones or find someone who can. PM Dotman (if I recall correctly) and he can get you some info on someone who can help with that. Short of that, you are going to need to buy several different boxes to see what shoots in your gun.
This is my 2 cents. There are some guys on here that have a lot of experience with this caliber and I'm guessing that they may add something.
I've been shooting deer sized game for the last 22 years with a 25-06, and that is at least 50 whitetails thanks to multiple tag options in my home state. Not counting coyotes. I shot partitions, seirra boatails, speers, accubonds and a few others. For the last 10 years approximately I've been using Hornady Interbonds, and I have no plans on changing. I primarily hunt big grass pastures, some timber, mostly spot & stalk. Most of the ranges average in the sub 200 yd area on deer. I can think of 4 that were in the low 400's and several over 250, and then there are the sub 100 yard shots. I've toyed with sciroccos but I like what I have as I have the time in the field with the bullet, and that fact keeps me from changing.
To the point, on deer the Interbonds (handloads) at any range for me have performed the best. They are accurate on paper, and hit hard at short to longer ranges for me. They maintain their weight within 90%+ every time (I weigh them if if recover them), most have been better than 95%. They are not devastating on meat and the kill clean if I do my part. Coyotes don't fair well against them either.
I'm at work and can give you my load data if you handload or are planning on handloading your own. I know they are SST 117gr. I have all the other info at the house. BTW I have the hand loading done by another, it is not by my hand. In the end though you are going to have to develop a load your rifle likes, or buy several types as tstowater suggested.
I know guys that say anything over 100 - 110 gr bullet in their '06' and they have problems. Again a rifle can be picky and you are going to have do some shooting to figure it out. I don't take my '06' to the field for elk but that's because that isn't my only rifle. I will echo the 25-06 maybe light for elk. If you already own the 25-06, I would start saving for an elk rifle. If you are looking to buy the 25-06 as a do all, you need to look at a different caliber.
Son killed a nice bull with a 25-06 and 115 combined technologies. Killed a mountain goat, killed a bunch of antelope and a few mule deer with it and that bullet. Seems to work fine.
I'm not saying you can't use the 25-06 for elk, just that it's not a recommended caliber. Frankly, I could kill them dead with my 220 Swift. Just not as much room for error. Also, depends where you are hunting and what you might run into.
110 accubond, I have a buddy that only hunts with a .257 weatherby and he's killed several elk from 80-400 yards with no prob. I wouldn't concern myself with ultra high BC on a gun like that.....a combo of good weigh retention and wound channel will do great at appropriate distances.
If you already own it you can make it work but I sure wouldn't buy one for the purpose. The margin for error is small for an elk and the bullet bc's are terrible in bullets that can stabilize in a factory twist barrel. The 6.5's and 7mm's are where the sweet spot is for a deer to elk rifle imo. Great bc's in the heavy for caliber bullets which translates into more retained energy and less drop and wind drift. Nothing wrong with the big 30 cals but you are carrying more rifle than you need unless you shoot long range. 280 ai , 7mm-08 , 260 rem , 6.5x284 , 280 rem , and even one of my personally loathed rounds the 270 win all would be a better choice for all around use imo but you can beat square pegs into undersized round holes if you work at it. There is always the story of killing a giant grizzly or elephant with a 22lr but a better plan is bring enough gun.
I kill elk with an arrow, the last one went 50 yards and toppled over dead. I think the caliber size and magnum power are over rated. Minimum caliber size in Colorado is 6mm or a 243, so your 25-06 will be just fine. Take high success shots and don't take a Texas heart shot, and you will be fine.
As for the bullet, I like the Nosler partition in my 25-06. Good luck and practice makes perfect.
Thanks for the suggestions guys. I figured that someone would mention the caliber size and Elk. I live in Western WY and am very aware of what it takes to kill an elk. I agree with thejones. Thanks everyone!!!
I started with the berger 115s with the idea that I would get the flattest trajectory. After smacking a couple hogs I decided I better change my load before deer season. Simply too explosive, lots of damage at closer range and not enough penetration for odd angles. I had best accuracy out of my gun with the 110 accubond and blew a clean hole through a small boar at close range. Still I wanted to the toughest bullet possible for the skinny .25 so I went to the 100gn Barnes TTSX. I haven't shot an elk with it but I can tell you it will penetrate a very long way, given proper speed. It will easily travel the length of a deer and exit with out turning the whole thing into jello. If you will only take a perfect, broadside shot, most any bullet will do the job.