Being a new guy on the block in the airplane section ( not to planes and RC.. ) i too over the years have drilled out some props with a drill.

Like to post this saying "for what it's worth"............

If you use a hand drill holding the prop against a block of wood or something simular (lot of work tables with shallow drill holes in them..) it will make the hole bigger.Is it going to end up Dead-on..............most likely not.Will it work on the plane,ya most likely if you don't care about proper balance (unless you drill the hole in the end of the prop )

But did want to mention a couple of things if this is the way you want to inlarge the hole.First would like to say some of todays drills are high speed,have a lot of power,and things can happen fast.If you are going to go this route...Wear a good glove that you intend to hold the prop with.Most of the time if you are going to just inlarge the hole a slight bit....what will happen if you don't have a hell of a good gripe on the prop and holding it tightly against something.........the drill bit is going to grab the plastic and run it up the drill shaft at an angle to where the flutes end and if you don't have a hell of a grip on it you will most likely be dripping some of that red stuff out of your hand or fingers.And in the end you have to ask yourself just how accurate can this new hole be.

BIGMIG

P.S. Been there and done this..........The old saying "live and learn" is not allways the way to learn.