Really depends on the bullets you are using. If your using a factory rifle with the standard 1-10 twist you are limited to bullets up to 120 gr. There have been some factory rifles that have shot the 125 and 130 gr Wildcat Bullets well also, there have also been many that have not handled these heavier bullets accurately so its a try and see type of deal.
Definately worth the time to try them because if they shoot well, they are a big improvement over the conventional bullets in 25 cal.
If your talking about a custom rifle
, you can get a 1-8 or even 1-7 twist and shoot some serious long range bullets such as the 142 gr ULD RBBT(7 or 8 twist) or the huge 156 gr ULD RBBT(7 twist) in the 25-06.
Personally, I feel the 156 gr bullet is to large for the 25-06 for anything but paper punching as it is a stout bullet designed to handle the impact stresses of much larger rounds like the STW and specifically the 257 Allen Mag where it is driven to 3300 fps.
In the 25-06 and a fast twist barrel, the 142 gr ULD RBBTs would be an impressive conbination. Offering everything the 142 gr class match bullets in 6.5mm would in a 6.5-284 or 6.5-06 chambering.
Really turns the 25-06 into a true long range cartridge easily capable of taking deer out to 700 meters with a well placed shot.
Its really a round with two very different personalities. In a factory rifle I would say that 700 meters is pushing the usifullness of this great round. In a custom fast twist barrel it is a totally different story.