What is this thing?

[Reflex0283]

Not sure what this is, it's been kicking around on my workbench for a while in a bag with the other hardware in the first pic. I think it's paintball related but I have no idea what it is, where I got it from, or what it does

[Ecapnation]

Part of a drop forward?

[Jonnydread]

Yeah I was thinking a drop that someone got really mad at

[Reflex0283]

I considered that, but that doesn't explain why there's that little lip and the whole blanking plate. I might have gotten this in a lot a while ago but that doesn't narrow any of this down at all