New challenge!!!! shell casing type???

Ok folks, I have a challenge for you. What is this shell casing? A Friend of mine gave them to me. He got them (about 150) from his grandfather

Funny Playing Shell (With Text) for Game Boy Pocket — Retro Modding

Redmi k40 mobile phone case liquid silicone redmik40pro protective case all-inclusive anti-fall Xiaomi k40 game enhanced version soft shell Chinese style men and women new 5g creative por national trend shell

Custom Egg Shell Pattern Nintendo Switch Soft-shell Case - UK

New Full Housing Shell Case Cover Faceplate Set Repair Part

2022 New Ns Switch OLED Game Card Storage Box Hard Shell

Classic Limited Edition Replacement Case Theme Style Shell With Buttons For Handheld GBA SP Shell Case SP Game Console From Botuo68, $7.32

Hard Shell EVA Travel Carry Bag Mario Case for Nintendo Switch

GBA Nintendo Game Boy Advance Pastel Green Replacement Shell for

1set New Game Console Shell Case for Nintend Gameboy DMG GB Classic Housing Cover with Buttons - AliExpress

New Style Multifunction Case Hard Shell Travel Carrying Protective Storage Bag for Nintendo Switch Red/Blue/Gray/Black

Shell (projectile) - Wikipedia