Patriot Ordnance Factory is located in Phoenix Arizona, and since 2004 has been the manufacturer of quality, regulated, short stroke gas piston weapon systems. POF-USA rifles were the first piston driven M16/AR15 type and AR10 type weapon systems offered on the market. POF-USA weapons systems operate without the need of lube, using POF's C.R.O.S. (Corrosion Resistant Operating System) technology. POF-USA offers RELENTLESS RELIABILITY on all of our weapon systems.