HTR over at arfcom and the 6.8 forum has done a lot of experimenting. He is in Tx and sells guided night hog hunts and mostly uses
6.8 SPC with night vision.

SSA sells a 140 gr Berger load, but mostly the issue with hunting bullets designed for 270 win speeds are the opening and or expansion at lower speeds witht he 6.8 and you have to have the twist for it. Not sure whats recommended for the 140 berger.

As far as killing power for normal game the 95 gr TTSX or the Raptor is about as good as it will get although the raptor BC is not too hot.

Beyond that into the 130 gr range, I would use a non bonded bullet, like maybe one of the tipped non bonded hornady or nosler bullets would work well at slower speeds. Maybe a pro hunter or gameking ??

If I remember right the 5X elk was killed at 350+ yards with a handload with a 110 gr Accubond.

If you go to arfcom to the variants section then click the AR15 Variants: Caliber-specific FAQs section and go down to the 6.8 SPC section you will find the data below. There is a ton of bullet and load info there.

http://i256.photobucket.com/albums/h...ngData_p01.jpg