Well, I finally made it to the range yesterday, Hornady whitetail 150 in .308 shot excellent in my rifle, so I put a chrony on it... they average almost right at 2900 fps 3' from the muzzle. I have read they are interlocks, but what powder??

If I am shooting that close to max loads in the cold, what happens when it's hot out?? I wouldn't want to load them that hot with H4895, or IMR4064....