'06 is a long action gun . The M24 was built on the long action to facilitate switching to 300WM not '06 . This sounded good in theory , swap the bolt and barrel and go from an 800ish yard rifle to 1300ish one , but in practical application it didn't work like that .
To switch the bolt out the new bolt had to be fit to the receiver as there is no real interchangability between rifles . This work had to be done by returning the gun to Remington because of the maintenance contract on the rifles . So the end user would be without the weapon for however long it took .
There were only a handful of M24's converted and almost exclusively for the SOF guy's and then they started making dedicated 300's like the MK13 and 2010 so it was a feature that really had no purpose .