TNT APS-X Hop-Up System Airsoft KWA MP7 Gas Blowback Inner Barrel Retrofit Kit (Length: 170mm)

"Unless you have a mock suppressor attached to your KWA H&K MP7A1, I would not recommend anyone to upgrade their inner barrel with this length as it will expose the long inner barrel. In this case, I recommend either the same one as this product where the length is 170 millimeter or the Maple Leaf Crazy Jet Barrel Set (180 millimeter). I upgraded my inner barrel with this length since I attached a mock suppressor to my MP7A1. Prior to this upgrade, my accuracy was totally off. Each time I shoot, the BB's frequently strike the inside of the mock suppressor shifting the BB's in all directions instead of moving straight from my intended aim. Once installed, it improved the accuracy, fps, range. The BB's no longer strike the inside of mock suppressor thanks to the tip of extended inner barrel being one inch below the tip of mock suppressor.