Nice bullet! Yeah I am already expecting some tight thread comments. Quickly screwing and unscrewing the threads repeatedly helps them smooth out. Mine broke-in great after a few uses.
Overall came printed really nicely using BBL Copper Silk PLA for the bullet and Elegoo Gold Silk fore the casing. tried cleaning up the threads but couldn't get it past a few turns and it ended up breaking. I may try again, but I just glued the pieces together for now.