I made some that started as a 5/16 tapered to 9/32. I barreled them to 1/4 on both ends. They would weigh in at 240-290gn.each I don't remember what spine I started with but I think around 50#. one blew up in dramatic fasion after about 20-30 shots from bows upto 65#I know it was to light of an arrow to start with but it was fun for a little bit. I only shoot them now out of lighter weight bows.
Mine looked very plain compared to yours. Very nice job. Have fun shooting the clouds, Thats what made me love archery.