Buzz Bee Ultra Tek 8 Nerf Blaster Scope Rail "Picatinny"
I bought the scope from aliexpress, under 4€ and wanted to mount it on the blaster. So I sketched the rail, printed it and it works like a charme.
For reloading you just pull the scope back.
The Blaster itself is super cheap on Amazon, 10€ and works really nice, it's a lot harder than the real Nerf guns!
The parts print seperately for easier printing, attached together with 2 screws and superglue. You don't need to use the screws, I added them mostly for a more mechanical look.