welcome. a valid point, me Im a tight wad and for years only used AR 2206 as I could load all my calibres with the same powder...it was great in .223 and ok in .270...now Ive bought some more 2213sc for big rifle as it was very accurate for me in the past...maybe you would be better finding a load that works and ORDERING powder from your supplier????
Vince will chime in and tell you varget/2208 as it should do most of your listed cartridges.
BLC2 is very good in .223 aswell.

ringet421, welcome to HuntingNut. There is some limited load data for the .243 with 75gr bullets.

www.hodgdon.com/PDF/SuperLever.pdf

when I'm using a powder without published load data, I use published load data with similar powders and ratio the loads to the powder-bullet combination I want to develop. Example, 80gr .243 uses 36.0 grains of Varget and 44.0 of Superform and are published minimums from Hodgdon. I then use this ratio for .308 Varget loads to determine a starting min load with Superformance. If you use this technique, do so at your own risk. It made me feel like I reduced mine. It definitely takes longer to develop your own load data this way. Published data is nice to have. Let us know what you find out.

Welcome aboard ringet421...as no-one else has offered mate, grab a beer and pull up a stump.

Gelan makes a very valid point regarding blended powders used by manufacturers. Unless you are able to get your hands on their "recipe" there is no way you can duplicate them powder.

Having said that, what Elvis says above is the best way to go...select a powder that offers good performance with each of your chosen calibres and get a stock of it from your local Gunshop.

He is totally correct when he says I will chime in with Varget...and there is a good reason for this...it works in so many calibres, and works well. My shooting buddy and I both use it in .223 Rem, .243 Win and .308 Win with very good results. Can't comment on the .300 Win though...I don't load for it so I really don't know how Varget will go with it...but nothing ventured, nothing gained mate.

Load development is not always easy, nor is it a simple process...and if it was, it probably wouldn't be as enjoyable. When you visit your local range, have a chat with other shooters...see what they are using and the success they are having. Once you have a heap of info, sit down and go through it, work out which powder you think might give you the results you want and then start your search for a source. Have a read of the OCW story on the front page of Hunting Nut and start your load development. You may even be able to utilise the same principle to selecting not just a load, but a powder as well. If you have to buy a few different powders, buy them in the smallest quantity you can until you have settled on THE powder. Once you choose the powder that works for your calibres...get your Gunshop to order in a larger container (I buy Varget, or AR2208, in 8lb kegs) so that you have a good supply of the same powder and batch to keep you going for a while.

The reason you see so much superformance on the the shelf is it's designed for very specific bullet caliber combinations thus has limited applications. Use it for something it wasn't designed for and it won't equal the performance of the common powders for that caliber.