You can of course have 2 of them ready, one in each hand, and do up to 2 attacks, but for more you need Quick Draw. Probably there are small weapons around in accessory books which allow you do shoot as many as you wish without "drawing", like the Skuriken mentioned, representing (for example) the idea of keeping them in the off hand, and passing them quickly to the right hand - that's at least one visual image for me.