Now all you need to do is use a real bullet for the nib. Get yourself some boat tail match bullets (168gr. for 30-06). Make a collet insert if you have a Beall chuck. Part off about 1/16" of the back of bullet to expose the lead core. Take a propane torch and melt all lead out of bullet. Then take a 1/16" drill bit and drill from back of bullet to enlarge the "bullet nib" hole to accept the refill. Then turn the bullet around in the chuck and part off the jagged edge of hole. I do these in batches of 15-20.
I really think these bullet pens look alot better with an actual bullet as the nib. There are some good tutorials out there that cover this and soldering in the 7mm tube to accept the transmission.