Big Yac, if you are getting 1" groups at 300 yards with 4895, your friends were very good to you and if you didn't have to do much load development to get there, you were very fortunate, but, it happens. I think you'll be hard pressed to exceed this level of accuracy. In the 30-06, the powders that I see recommended the most for accuracy and great all around use are IMR-4064 and H-414. Reloader 15 (which is slower in burn rate than 4895) can sometimes surprise folks as an accuracy powder and Reloader 19 is suitable for hunting loads, but it is a bit on the slow side for 30-06, but that doesn't mean it's carved in stone, especially if velocity is what you need in the hunting load. IMR or H-4350 can also be used for 150, 165 and 180 gr. hunting loads with success. IMR-4350 is hard to beat for hunting loads in a lot of calibers that don't require something even slower, i.e. Magnum rounds, and even then it will work well in a lot of them.
I don't load the .454 Casull, but I don't use 2400 in any of the Magnums that I do load. I do have some recommendations, so take the previous statement into consideration. My oppinions are based on powder burn rates and pressure characteristics. Before I used 2400, I would look at the competition. Hodgdon; H-110 and maybe even better, Lil Gun. Winchester; W-296 because that's all there is. H-110 and W-296 are very similar powders that are made for them by Primex, but I think I would keep looking because the .454 is a very high pressure cartridge and something just a bit faster may prove to be better. Lil Gun would get the nod over H-110 or W-296. Accurate #9 could be great and is slightly faster than Lil Gun, but Accurate is pushing the newer 4100 for this use. At almost Identical burn rate to AA#9, is Ramshot Enforcer (Western Powder Co.).
I just don't need the power of the .454 and I tend to shoot a lot of rounds when I shoot Magnum Revolvers, so I definitely don't need that level of constant recoil. If I started loading the .454 Tomorrow, undoubtably I would use Ramshot True Blue and some may not be familiar with it. It is faster than AA#9, but slower than AA#7. It is a great powder for slightly less than full throttle velocity while still giving decent load density, but the thing I can't overlook is the standard deviations it achieves with maximum loads, so I'll list the three from their #3 load guide and more data is available at their website: www.ramshot.com
These are the Max. loads. with True Blue. from a 7.5" barrel (not listed) The Hornady 240 gr. load is reduced by 10% for a start load. For the 300 gr. XTP and the 300 gr. Nosler Partition, No reduction is recommended.
240 gr. Hornady XTP, Rem 7 1/2 primer, Win. case, OAL 1.765" PC 20.0 grs. velocity 1662 FPS @ 46,460 PSI. Standard Deviation is 5!
300 gr. XTP Rem. 7 1/2 primer, Win. case, OAL 1.760" PC 19.0 grs. velocity 1552 FPS @ 52,030 PSI. SD is 5!
300 gr. Nosler Partition, Fed 205M primer, Win. case, OAL 1.760" PC 19.5 grs. velocity 1557 FPS @ 53,570 PSI. SD is 6!
The SAAMI recommended Maximum Average Pressure for the .454 is 65,000 PSI, so you can see that you are getting excellent performance with more than a 10,000 PSI safety margin and getting single digit Standard Deviation in the bargain. This is EXTREME ballistic uniformity for a round this powerful.You will find higher velocity load data with other powders, but it is not likely that SD's will be listed nor will they likely be single digit.