A friend has a casing for a 243 and wants a pen made from it. (First deer kill). Can one be made from such a small caliber? Any pics or ideas would be very helpful.
Do you mean 243 Winchester? 243 Win is basically a 308 Win that has been necked-down to 6mm. A slimline nib won't fit, but if you want to use a real bullet for the nib, then it can be done without problem. Just don't use a bullet with an oversize hollow or soft point (such as Nosler Ballistic Tips).
I've made some from 243 cartridges. Made the nib out of bullet. There is or was a very good tutorial in the library here that is what I learned from. It showed how to do it all.