Last time I checked, X-Reload had the tubes in stock. Not sure about the dies.
A cheaper solution to the feeder tubes is to go to your local aquarium store and pick up 7/16" clear plastic tubes. They come in 3' lengths so you can either use the full length or cut it in half. Apply a wrap or so of electrical tape to one end so that it fits snugly into the die. Drill a hole just above the top of the die and push a cotter pin through it to act as a stop when you fill the tubes. If you use a full 3' tube, it's a bit flimsy so you'll need to sheath it with a 9/16" tube or support it from the ceiling.
Not my pic: