I've always wondered why Liberty won't make this in a lighter grain for the 5.7. They make it in the 4.6 and they certainly could make a lot more calibers with this design and have a good thing going.  
I was curious as to whether this super long bullet would stabilize in 5.7x28mm since both the FSN, P90, and PS90 both employ 1:9 twist barrels. If anything now you know and knowing is half the battle :D I wonder if I can source one of CMMG's older 1:7 twist barrels :D