there are two possible sources of problem here:
the spur, if screw-type, is dull so it won't pull the auger into the wood
the blades of the auger are dull.
i would suggest getting a needle file and having at the blades from the inside edges. get out any nicks and finish with the finest grit stone you can fit in there. lightly dress the outsides of the edges, but you don't want to make the hole size smaller. do what you can to remove the burr with light strokes.
if the spur is damaged, you can try using a knife-edge needle file to recut the threads, or you could shape it into a spike point, meaning you will have to press down much harder vs just turning it and letting it do its own work.
augers are really neat tools, i use auger bits with my brace for alot of rough woodworking jobs (building benches and other basic things)