if you read it PROPERLY there should have been no reason to ask your inital question- being lyman, i know it well and KNOW THE INFORMATION IS RIGHT THERE- THAT'S A GOOD MANUAL-i use ww748 for almost everything except the very big magnums, but i've never seen a load for the 7.62x39 with it- and while 30 ( 308) will work, they're typically 2 thou UNDER bore and you need 311-312 diameter bullets
but evert rifle is different and what lyman says may not be true necessarily- IT'S WHAT THEY FOUND DURING TESTING WITH THEIR PRESSURE BARRRELS- your actual results may vary- i've got 4 m14s and each one of them while liking the 748, takes a slightly different powder charge - recommendations mean nothing in the real world- if you're looking for "shortcuts" to a good load , you won't find any- it takes time to work up to a good load, and if you vary one component, you have to work all over again-