I have no doubt that the 140 Accubond will get the job done. I use the 130 Accubond in my 264 Win mag on deer. I live on the wrong side of the Mississippi so no elk experience. I have only recovered one 130 gr Accubond every other has exited even as close as 80 yards. The one that I recovered was from a large body buck shot at 111 yards that was almost facing me with just a slight left shoulder angle toward me. Bullet was placed on the edge of that shoulder and deer drop on its butt and fell over dead. On dressing it I discovered that the shoulder was smashed, lungs were wiped out and while cutting up the meat I found the bullet against the smashed ball socket of the right ham. Bullet was a text book mushroom that weighed 87 grs. If it will do all that to a deer I am sure that the 140 will hammer an elk. Bullet left the muzzle of my 27 3/4" Shilen barrel at average 3350 fps. I use 66.5 grs Retumbo, CCI 250 primers, WW case reformed from 7mm Rem mag cases, with the 130 AB at COAL 3.450, average 3350 fps and drives tacks.
I have never tried RL25 but have heard good things about it in the 264 Win mag. If you have a max of 60 grs listed then back off 10% and do a work up and see what you get. It all depends on YOUR RIFLE. My rifle has a tight chamber and I can not get to the max loads listed for Retumbo without too high pressure. A friend of mine uses 1 grain over max listed which is all he can get in the case in his rifle with no pressure signs because his rifle has a somewhat sloppy larger chamber. Good luck and good shooting.