They will both kill, but neither are strong bullets. If you are just using them for deer, then flip a coin. I would not use either. The standard 129 Interlock is a much better bullet for hunting.
I was looking at one of those to play around with....
But I admit, I'd be playing around with bullet weights from the 85 grain HP Sierra, up thru the 100 grain Ballistic Tip...
if I thought I need something heavier, the 120 grain ballistic tip would be it...
at the speeds possible ( really lack of it) in the 6.5 Grendel in a bolt action, the 85 grain HP, the 90 TNT and the 100 grain Nosler BTip. or 100 Sierra HP... are more than up to the Task of dropping Bambi and/or his big brother... 250 yds and closer with NO problem...
if ya have to use an A Max... don't overlook the 100 grain version... I sure wish Hornady hadn't canned the 100 grain SP... that would also have been a great Grendel bullet..