Now you've done it!
Soon you'll find yourself at the range shooting just because you don't have any empty cases.
I think hand weighing each charge is probably a good thing for a beginner. Once you get a rhythm going, you can charge cases pretty quick. The shavings could be from a couple things. Not enough flare......if you can start a bullet with your fingers, that should be enough. Too much crimp......sometimes when roll crimping, you will get a bit brass off the top of the case, or like rwilson said, the crimp is starting too soon and dragging the mouth of the case on the bullet.