Latest video update from Massive HK posted at you tube. For those who have bought their Jing Gong M4A1 Blowback Rifle, and plan to upgrade it, this video shows how to up install a hard recoil buffer. There's really such a hard kick on the Jing Gong rifle in the video. With this, you can now also upgrade the body into metal. Just check the video below, it's that easy.

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