My impression is that folks think of the .44 Special as a big cream puff, which it is at the lower levels but when you load it up close to those Keith levels it gets downright frisky. He used 17.5 gains of 2400 with his 429421 bullet but when I loaded for my .44 Spl Flattops 16.0 was as high as I cared to go.

Gunnery, gunnery, gunnery.
Hit the target, all else is twaddle!