Aubrey, I've looked at this issue quite a bit and concluded that there is no upside to the 6.5x47 for 300 meter ISSF shooting. It is unlikely that it is more accurate than the 6BR,and by saying unlikely I'm being nice). The added recoil is always a negative. No upside.
As to the 6mm wildcat version,s) of the 6.5x47, again, I have to ask "why"? The 6XC already exists, it is a cartridge for which standardized dimensions,reamers, dies) exist, for which excellent factory brass is available, so what's to be gained? The small primer is the only real difference and in a cartridge of this size I don't believe it amounts to any real gain, especially if a milder primer is used in the 6XC, such as the Russian or CCI BR2.
I shoot 4 cartridges for all my matches, 300 meters to 1000 yards,not all cartridges at all distances) they are 6BR, 6XC, .308 and 30-06 - not a wildcat among them and I have never found a solid reason to venture into that pool.
In fairness, I should say I have a .22 PPC which I built for 300M and while it is,now) very accurate, it was a major headache to get there and I wouldn't do it again. I don't use it much either, it's just simpler to shoot 6BR.