When looking at Hodgen's data for 748, they appear to have just reprinted from the old Win basic manual. In that manual, when you look at the pressures listed, 748 is downloaded significantly for some loads in 223 .

Most other manuals list 748 for 125, 150, 168 grainers in 308. It's burn rate is on the very slightly slower side for semi, very slightly faster side for bolts (opinion).