Not satisfied with the recoil kick of the Tokyo Marui M4A1 MWS GBB Rifle? Mach Sakai found an upgrade part made by Frontier1 of Japan and it is a reinforced hard recoil buffer that can give an heavier kick. It weighs 221 grams and thus it's much heavier than the original Marui buffer which weighs just 24 grams. Watch the video below to find the difference: