This code needs to be included in the plugin for the guns to work corectly. Otherwise you would be shooting guns instead of balls.
public class ProjectileLaunchListener implements Listener {
@EventHandler
public void onProjectileLaunch(ProjectileLaunchEvent event) {
if (event.getEntity() instanceof Snowball) {
Snowball s = (Snowball) event.getEntity();
ItemStack item = s.getItem();
ItemMeta meta = item.getItemMeta();
if (meta != null && meta.hasCustomModelData()) {
int data = meta.getCustomModelData();
// convert from gun to snowball
if (data > 0 && data < 17) {
meta.setCustomModelData(data + 16);
item.setItemMeta(meta);
s.setItem(item);
}
}
}
}
}