This is a simple mod you can do on a Firestrike. I printed out the "Nerf Firestrike Barrel Extension by makersendinfo", and created a piece which when glued in the inside of the barrel, depresses the AR letting you fire short length darts without needing to use a ramrod. The "Nerf Firestrike Barrel Extension by makersendinfo" is used to keep long darts from falling out. It friction fits well onto the barrel, and is easily removable. When firing stefans of half lengths, simply take the barrel extension off and load, as seen in the pictures.
Note: Make sure you clean out the barrel after you use hot glue - it will drastically reduce performance, and you can have the dart post in - it will work either way. Also, since this will block some of the airflow, a slight drop in performance for full lengths will be apparent.
Hope you enjoy!