When you really think about it this argument is rather silly. A 25-06 was always intended to be a hunting cartridge to be used in hunting rifles that were accurate and effective out to at least 500 yards. The rifles usually weigh about 8 1/2 pounds with normal hunting scopes. These hunting rifles cannot be compared to true long range rifles in 6 mm or 6.5 mm that weigh 12 pounds, have a custom barrel, and a scope that costs $3,500, and are only fired using a bipod. Why would you even want to compare the performance of a $900 rifle and scope to a $6,000 competition rifle? Also, the argument that there are no good long range 25 caliber bullets is pretty close to being dumb. It's not hard to get a 25-06 to shoot minute of angel out to 500 yards. Sierra, Speer and Berger all make bullets that will do it when matched up with good cases and powders like IMR 4831, Reloader 17, 22 and 25. Shooters who own a 25-06 don't need to rush out and buy a 6.5 mm rifle just because someone says there are no good 25 caliber long range bullets.
For hunting 500yds IS long range IMO. Again I have little issue with folks shooting farther with correct gear, practice, and confidence, BUT for a good many of us anything beyond MPBR is probably edging our limits, and for others MPBR is probably too far. 25-06 offers plenty range and power for most of us, so does any common round from .243 on up, use what u like within your comfort zone.
But for a lot of target and competition guys 500s just where its starting to get fun. At longer ranges, BC starts to matter more, and more, wind drift becomes even more of an issue.
Take the plots that weve talked about for the 115bergers, which are the highest BC .257s generally available, and compare them to any of the heavy for cal, high bc bullets available to the 6.5s, or even the 6mms.
The .257s need an extra 300fps to stay with the 6.5s out to 500, and begin losing ground after that. I didnt get to shoot my 6.5CM or my .250 much past 400ish yds, and nothing official just plinking at rocks, but i HAVE shot my 7Mag, and .300s out to over 800yds.
My 7s have universally shot 162Amax, 160TMKs, or 168 Berger VLDs, with bcs in the 600s. My .300s were shot mostly with 168grn VLDs, or 180grn Balistic tips, with some random 125s tossed in for good measure. BCs of the 30s ran probably from about 480-500 i THINK cant remeber, but if memory serves they are pretty close to that.
1st round hits for me outside of 400-450yds are rare, but once ive got the drop figgured landing rounds on target was alot easier with the 7s than it was with the 300s. To be fair i DO also shoot the 7s better than the .300s, but the random...wow that got blown farther than i expected didnt happen as often with the 7s.