The difference is unimaginable!! Especially with a super accurate round like the .223. Even the most "premium" ammo can't match the accuracy of handloads. If you're going to shoot a super accurate round like this you MUST handload. As far as tips and advice get a couple of books on the subject. Lee has one of the best on the subject. There are a few others but the titles escape me at the moment. Attention to detail and round to round consistency are the keys to extreme accuracy. This means everything from case preperation to crimp pressure. Just be warned, IT IS ADDICTIVE! It's a blast though!