Yea, I read an article a few years back where a well known writer (can't recall the name right now) hunted in Africa with his 30-06, which had a 26" barrel as well, and he got special permission to hunt Cape Buff with it. Seems he'd had some neck injury he was healing from and couldn't handle the recoil of heavier rounds.
Anyway, he was pushing a 220gr solid bullet somewhere around IIRC. Gosh that's driving me crazy not remembering all this. He's a Hispanic fellow been writing for 40-50 years too, both bun and archery hunting.
Ha, I remembered his name, and found the article. Sam Fadala, and here is an excerpt from his article.
"Sometimes penetration and bone damage are paramount. As some may recall from an earlier article (“Happy Birthday, .30-06″, May/June), I had official permission to go for a Cape buffalo with a .30-06. A come-apart bullet would be a disaster in this instance. I chose a 220-grain solid cranked up to 2,615 fps from the 26-inch barrel of my rifle. The bullet entered the right temple, stopping under the hide of the left shoulder after more than 40 inches of travel. "
Here's the pic from the article.
Anywaylooking at Hodgdons reloading data they list the 220 max at 2450 ish and that's from a 24" tube, so it sounds like ole Sam was running warm loads as well, but HE got 200 fps
Here's the link to the article.