The 6.5x47 does not have the same capacity as the .260 Rem. I don't recall anyone saying that it did. The case is about 3/10 shorter, but it does have a sharper shoulder and a longer neck. The problem with the .260 is that with 130-140 grain bullets loaded to magazine length, the base of the bullet is pushed past the point of the neck/shoulder and this can compromise accuracy. Admittedly this is extreme accuracy and from a light barrelled hunting rifle may not be significant, but it is still a factor. The longer neck of the Lapua round obviates this with all but the longest bullets (longer than 139 grain Lapua Scenars). I think at the end of the day the difference in velocity that should be achievable from like barrels is likely to be less than 100fps. The 6.5x47 is certainly capable of 2950fps from a 26in barrel and probably up to 100fps more using powders like RL17. That is not really a factor for me as I plan to use a 22in barrel with an Ase-Utra suppressor and will be happy with 2750fps or there abouts.