I was wandering through my local BassPro, found some Winchester 748. It has been on my 'list' as a good 223 powder, so I grabbed it. While researching possible loads, it seems that it is not recommended for heavier bullets, not much over 60gr. Is it because it's a ball powder as some have said or the burn rate? I recently bought some 75gr bullets to see if they would work in my gun, (1:9 twist). I had bought some Reloder15 which is 'supposedly' better for heavier bullets. I loaded 10 75gr rounds just to see, not only did they shoot and not tumble, (100 yards), they grouped real well, pleasant surprise! Reloder15 isn't a ball powder, not sure what type it is, looks like a bunch of short pencil leads, so I'm thinking there might be some truth to this?