Here is a link to the post showing the 50 BMG using a bullet for the tip.
http://www.penturners.org/forum/topic.asp?TOPIC_ID=21321&whichpage=2#220607
Since there seems to be some interest in the 50 BMG, I will put together a tutorial, with pictures, of how to make them. The demo on Saturday was a descriptive overview of how to make a 50 BMG pen. It did not show the individual steps, just a description of them with some hints and tips thrown in.
The tutorial may be long since there are several options to choose from. Such as Cross or Parker refills, and bullet or wood tip assemblies. This is going to take a while to do since I will probably come up with more modifications/improvements to the process as I produce the tutorial. I guess this is a curse of engineers, nothing is ever "good enough", we always want to improve things.
BTW, I have plenty of casings and bullets in various stages of completion which I prepared for the 2007 MPG (thanks Greg for organizing this) available for sale. PM me if you are interested.
Paul in AR