I wonder what would happen if you took a wood barrel and spun it down to size. Then put a dowel through the pen to a piece of wood and glue it there, to hold the pen upright and steady. Then get out the smallest birdshot you can find...low power, like a 22 birdshot round. Shoot the pen. Then load another round and go shoot the pen again from 1/3 around..so you shoot the pen 3 times from 1/3 around the pen. The pellets and pattern will be all around the pen and embedded in the wood. You'd need a strong wood, but not a really hard wood...I'm thinking something like a Birch maybe. Then you can CA over all the pellets and assemble your pen. This is all just a theory I came up with on the fly of course. Does it work, I don't know, but it sounds pretty cool in my mind!