You will have to choose bullets and primers that fit your cartridge. Then you will have to choose a powder that works with the bullet weight you choose for your cartridge. All this info can be found in you manual or online at a Powder makers site like Hodgdons. Some powders will work better than others for some cartidges or rifles. Some work well in many, some only in few etc.
For your 30-06 and 308 you will need .308" diameter bullets that you choose and Large Rifle primers (Magnum can also work, but regular will be fine). Bullets for hunting and bullets for target shooting will be made differently in some cases with the target ones not being suitable for shooting an animal such as deer. Sierras Match Kings are hollow point for example, but not intended for hunting.
A couple powders which should work well in a wide range for these calibres and have load data found in most manuals would be Hodgdon Varget, IMR 4895 and IMR 4064. There are many others too and some more suited to certain bullet weights etc.
Just for example;
Sierra 168gr .308" HPTB
Win Large Rifle primer
IMR 4895 powder
And your 308 or 30-06 cases would work in either calibre with the loads found in a manual for 168gr bullets.