it's about 6-7" across.
Axial piston pump? Sure looks like a thrust/valve plate to me.
sic semper tyrannis
https://m.aliexpress.com/s/item/2023...8.4.154.buINdk
Must be a pump body.
How old is it? They made revolver cylinders for naval guns in civil war looks like one...
New Non Restricted NEA gun?
"Never trust a government that doesn't trust its own citizens with guns...."