When you are crafting a dispenser, if you click the dispenser icon in the recipe book to autocraft a few times, you will see that one bow goes in, and says that the bow is stacking. When you take it out, all the other bows disappear. (See image)

(Also, it takes the bow from your hotbar, where good bows are stored. I've accidentaly lost one of my bows this way, so maybe make it take the bows out of the inventory before the hotbar)