MtJerry: 2400 is too slow for loading semi-auto pistol cartridges, including the 45 auto. You may get the pistol functioning, with proper feeding and ejecting, but 2400 will not burn completely and may foul your barrel. You may not get consistent buring or accuracy. I tried using 2400 when I developed my wildcat auto cartridge but it would get me neither the velocity or the accuracy I wanted. I wouldn't use it for the 45 auto.
However, that being said, it is an excellent powder for almost all revolver cartridges. But, this is just my 2 cents worth here. Mikey.