Barrel Plug for prop guns

I made this to go with the prop Carnifex I have here. The bottom part has a hole for the head of a 3/8" bolt, and the top part will just glue onto it.

I will print this in neon orange, so if conventions or local laws require an orange barrel plug on toy guns (or things that remotely look like guns) then you can just thread this assembly into your prop and be in compliance.