Here's the deal: I just bought the Lyman 49th edition reloading manual, and so far I like it. I'm thinking about making it my"go to" manual. There is just one problem. I load mil-spec weights in my .223s ( 54 grain and 62 grain) but the manual doesn't have data for those weights but it does have data for 55 and 63 grain bullets. Am I OK to substitute mil spec weight for a bullet that weighs 1 grain more, or am I asking for it? Thanks.