I'm awfully late to this discussion but it sure is an interesting one.
I really like 2400, old lot or new, and could happily live with it for straight-walled magnum revolver cartridges. I do like H 110 for use in my .44 Magnum.
Some years ago I worked up to the maximum listed loads for several powders as published in the 1978 edition of the Sierra manual, using their 240 grain JHC bullet, and tested them over the chronograph. The H 110 load achieved the highest velocity in my 8 3/8-inch Model 29.
Here's the findings from the maximum published loads of the powders tested from slowest velocity to the fastest.
IMR 4227 1238 fps
Unique 1246 fps
2400 1419 fps
AL8 1430 fps
BlueDot 1461 fps
W 296 1510 fps
H 110 1542 fps
These were definitely max loads and all but the IMR 4227 and the AL8 exhibited some flattening of primers.
I also did same thing with the Sierra 180 grain JHC bullet and the following powders with the following results.
Unique 1538 fps
2400 1620 fps
H 110 1814 fps
By backing off 1.7 grains from the Sierra listed maximum load for H 110 I ended up with a velocity of 1478 fps with their 240 grain bullet. It is potent, accurate load that has worked well for me for hunting and for when I was using the .44 Magnum for silhouette shooting.
For lead bullets though 2400 powder is the best choice and gives great accuracy with quality bullets. My favorite lead 245 grain SWC load with 2400 clocks 1386 fps from the long-barreled Model 29.
