POTD: X-Rayed Lower Recevier

    Similar to X-Ray Guns, someone took their lower receiver and X-Rayed it. However this is a polymer lower. It almost looks invisible in the X-Ray image. I am surprised at the position of the buffer retainer. Look at how far forward it is canted. Perhaps that is just a characteristic of the polymer lower or do all buffer retainers lean that far forward?

    Does anyone recognize the stock? It appears to have an adjustable cheek riser. I am interested to know why there is a horizontal coil spring in the stock.