/vr/ - Retro Games

>>5320552
There's a legal and practical aspect to it.
Because with actual grenade shells, those are legally "Destructive Devices" in and of themselves (a Destructive Device can also define any firearm with a bore diameter larger than .50 caliber/12.7mm, which hasn't been determined to have a "sporting purpose", thus a grenade launcher can also be a Destructive Device).

What this means is that each live grenade has to be registered in accordance with the National Firearms Act, and requires a $200 tax (one must also pay this tax when transferring ownership of it), and in the case of grenades, each single one would require individual registration and tax. When the grenade is fired, you would have to report it destroyed to the ATF.
Further, for most explosives, there's a lot of very particular rules about storage and transportation.

Looking at a chamber adapter like the one pictured there, it may or may not require registration as an "Any Other Weapon" (kind of a blanket term the ATF uses for not just smoothbore pistols, and disguised firearms such as cane guns and pen guns, but a lot of 'miscellaneous' things as well), and either you only register/transfer it once, or you don't at all, and then you can just shoot normal shotgun shells and signal falres with it, or seen in that other image, .22 Long Rifle cartridges, either which will be MUCH cheaper and easier to source and store than actual 40x46mm grenades with explosive payloads.