That doesn't surprise me.
And my experience also tends to indicate that load density can make a difference. The IMR4350 load I use in my .375 H&H with 300-grain bullets is 80-81 grains, exactly how much depending on the lot, which DEFINITELY fills the case!
As scenarshooter pointed out recently on another thread on the same subject, you never know what any load will do at different temperatures until you test it at different temperatures.
