GORILLA MACHINING AR-15 5.56/.223 MARKSMAN UPPER RECEIVER

Gorilla Machining custom build, pick up a non-barreled or stripped upper receiver. We carry top brands, manufactured with high quality materials and process, ensuring the best quality parts for your AR-15 ,M4, M16 AND AR-308 build. These upper receivers are manufactured in house with 7075 aluminum aircraft material and mil-spec components .

Gorilla Machining AR-15 Upper Receiver 5.56×45mm NATO (official NATO nomenclature 5.56 NATO, fyv-FYV-six) is a rimless bottlenecked intermediate cartridge family developed in the late 1970s in Belgium by FN Herstal. It consists of the SS109, SS110, and SS111 cartridges. On 28 October 1980 under STANAG 4172 it was standardized as the second standard service rifle cartridge for NATO forces as well as many non-NATO countries.Though they are not entirely identical, the 5.56×45mm NATO cartridge family was derived from and is dimensionally similar to the .223 Remington cartridge designed by Remington Arms in the early 1960s.