I've used Remington Core-Lok'ts in both 130 and 150 grain. Like others have said, get yourself several boxes of ammo, different brands, different grains, and let the rifle tell you which one it likes. I use a Savage Model 111 in .270 and have found mine 'prefers' the 150 grain. Core-Lokt's have never let me down and have repeatedly proved to be a one shot, one kill round. Any issues with not dropping the deer with a Core-Lokt with a single round have been proved to be the fault of the nut behind the trigger and NOT the round in the chamber. ((Nahhhh, say that isn't so!!!))
Oh, for giggles and grins, my daughter bought my son-in-law a Remington 710 in .30-06 and he has never had any issues with it. He uses Remington Core-Lokt's in his as well (just not sure of the grain). Don't have a .30-06 so I can't provide any input on that caliber, figured that .270 is plenty enough for any whitetail here in central Texas.
Just my $0.02 worth . . . . .
And that's after finding two pennies walking through a Wally World parking lot.
Anyone else out there using Remington Core-Lokts???