One .30 cal projectile to rule them all? (.30-06, .308, .300blk, x39 and x54r)

Howdy Reloadit!

No0b boob here, sorry if my question is simple and something obvious to most. Just got all my equipment (LNL AP) and everything set up for .223. I will not make the jump to a new cartridge for a while, but I would like to do a .30 cal next. The problem is, I don't know which to pick next.

I own all calibers (except 300blk) but was curious is there was a single projectile, maybe around 150grn that would be compatible across the board. If so i'd want to pick up a bunch of them and hopefully save by economy of scale. Mainly looking to plink, and possibly hunt. Accuracy past 1MOA at 200yds is fine. If I were to hunt i'd prob pick up specialty projectiles.

My major concern was would the Russian weapons need .311 projectiles or would the .308 work fine? Could I grab a .310 projectile and use it in everything? I also think my AK has a US made barrel and is .308 but chambered for the x39.

Thanks in advance! Feel free to educate me on something you think I should know. Cheers!