I appreciate all of the replies. I might have been a bit vague in my initial post. For the most part, I would say that more than half of my shooting is done with only a couple of rifles, and by and far with one in specific a .308 with a 16.5" barrel.
I understand, and very much appreciate the info provided, about how much it takes of this, to do that for peak efficiency. My main reasoning behind this was to have two powders which would more or less be used in a .243, .25-06, .270, and the .308.
Granted there are better powders for the .223, and for the, 30-06 and for my STW and, so on, and so on. I know this, and am not looking to crank out several hundred rounds of any one caliber specific load. I have loads which shoot very well in all of the rifles I am loading for, and most, if not all, will shoot something good with these two powders. I love H4350 and it was one I had a hard time getting past, but for the heavier bullets in the bigger stuff, it just doesn't get the accuracy that the H4831 does. Since I don't shoot them but on occasion I figure that will be fine. Same for the .223, I have probably enough ball powders to shoot the barrel clean off my Contender. Yep that one is a 14" barrel, and it simply loves a 45gr bullet over anything else, for which there is a load or two for H4895 that works really well. Granted they might not be the utmost in efficiency, but when I load X powder in Y caliber, it goes bang, and odds are high it will hit where I aim, and drop just about any critter it is pointed at right then and there.
I have other powders on hand for specific loads, I am simply tired of and do not want to have thirteen or more different half bottles of powder around for the once in a blue moon chance, I decide to crank my 303 British up, or drag out the .300 Savage, or run my '06 at 3000fps with the 165gr loads.
I have been through all of the powder testing, and bullet swapping I care to, and while new powders are wonderful, they also might be like the Accubond or the latest ultra super short whatever, and just be something else to sit on the shelf. I have come full circle and am trying to get back to the standards, and cup and core velocities. Heck I even got a couple of bullet molds to try out here shortly. I am looking for simplicity, or standardization of my stuff. I have had enough of wondering whats coming out next. Just gimme a truck that will get from point A to point B, and I will worry about the mileage.
Heck for excitement, I have some 150gr cast bullets to try out in my Ruger Blackhawk in 30 Carbine, or work up some 300gr loads for my 454.
Thanks for sharing, adding to the mix, and all. I do appreciate it, it has given me more to consider.