This company is all American made AR parts. They do government contracts, make parts for other manufacturers, and sell to the public. I've met one of the owners while I was taking an armorer's course in Moyock, North Carolina and have purchased from them several times in the past. They are legit, the parts are good.
https://unbrandedar.com/product-category/ar-15-parts/sale-items/
https://unbrandedar.com/product-category/ar-15-parts/sale-items/