Could be your arm action is more like that of a pitcher or outfielder. Hard to say without seeing you throw, but if you're bringing your arm back and around like you do when you pitch, then you are losing valuable time (unless you pitch like Keith Foulke)
. The SSs I see have a short-arm technique where they are very compact, not wasting time rearing back with a long arm behind them. Get set, load your arm up immediately to launch postion near your ear. Sorry about the ragged description, but that's as near as I can desribe it. Watch some MLB guys on TV, other good SSs in your league. This isn't really a power issue, but more of a time issue. Some other guys here can probably tell you more about it than I can. Good luck.