[stingray656667]

I've been looking at Thompson parts kits recently and have come across a few lower receivers that have a rectangular recess machined into the lower receiver behind the fire control group and just above the area where the shoulder stock screws are. Not all have this and I'm wondering what the purpose of this machined recess is if there is one. Any help would be appreciated. Thank you very much and Happy New Year to all!

stingray656667

 

[ComNtakeIT]

I believe it was for the quick detach stock option I also remember seeing a prototype folding stock at some point that may have used that same attachment point... if I’m understanding what your explaining