Action proto type? Barn find

[cornshank]

Found in barn , what is it ?
Thanks

 

[shortgrass]

Oh! No! A "ghost gun"!

 

[cohunt]

I remember the days ( before internet) when there were books with full size schematics and detailed instructions of how to build full auto drop in triggers for guns like 10-22, m1 carbine, ar15, etc.

That device looks similar to the 10-22

 

[Orange Dust]

Looks like a home made crossbow trigger to me. DIAS I remember weren't nearly as elaborate. I've seen them made for an AR out of a piece of feeler gauge stock, and for an HK a bent paper clip will do. Select fire is a completely different cat.....

 

[762x51]

the u-shaped piece in the middle photo looks like a feed ramp to me. hard to guess at what it's for without having it in front of me