AR-15, M16, M4, Stocks, made by Magpul, Vltor, Cavalry Arms, Stag Arms, milspec and commercial dimentions. ridiculously easy. We also offer our patented AR-15 and .308 Easy Jigs which is the first 80% lower jig that makes it ridiculously easy for a non-machinist to finish their 80% lower in under 1 hour with no drill press required. M16A1 Upper Receiver Forging. MAKSEC Group. March 19th, 2016 • Part Number – 12576279 • Reverse Engineered utilizing all the appropriate Federal Government ...