Here's an experimental SKS model built by Simonov in 1954:
http://server6.theimagehosting.com/image.php?img=sim1.97d.jpg&album=0&fullsize=1
http://server6.theimagehosting.com/image.php?img=sim2.jpg&album=0&fullsize=1
Russian weapons designers have always been given free reign to experiment. Not everthing works out but often some real winners arise. Such is the nature of experiment
A bit more daring and leeway granted to Western designers might be advantageous.