strictly my layman's opinion, to be taken w/ a grain of salt. the 6XC is roughly a "short" .243 that has about 7 g less volume than the .243 win case. the advantages it is designed to provide, longer barrel life, less case stretching, etc., make more sense in high-volume target shooting than for hunting. for a Blaser hunting rifle, I'd just assume use a .243 case for the 105 A-Maxes, and at least a 1-9" twist barrel (does Blaser offer that fast a twist in the .243? thats a consideration too).
all that being said, the 6XC seems to be a great cartridge, and I end up liking just about anything that starts with the 22-250 case. if you don't mind the more limited availability, etc., go for it.
The other important part of the design was to mag feed using ar15 platform magazines that David Tubbs uses in his Tubb 2000 rifle. The mag feed element was an essential part of the design for use in rapid fire strings of
cross course competitions. The 6xc upped the ante over the .223 in bucking wind at the longer distances
