Ok well since I transformed my M16 into a M4 the Dboys front set i put on it has 2 things. The barrel sort of has barrel wobble. It's not like when i move the gun left and right the barrel goes that way. Its wear if i greab the barrel i can make it move up down left right or w.e way i want a few mm. Now the problem that is wierd to me is that my Dboy's rails can turn 360 and more. The rail itself can spin around and round. Is this supposed to happen? Here's a link to the product.
http://www.torontoairsoft.com/product.php?id_product=82