100M Magnus-compatible carbon steel one-piece outer barrel for VFC HK416

This outer barrel allows you to install the 4UANTUM MAGNUS hop up chamber, probably the best AR GBBR hop up chamber on the market. 

Why should you replace the original barrel & hop-up with this?

• A stable hop up, no need to redial your hop up mid-game because of the unstable guide-rod hop up system.
• One-piece design means no more wobble between the base and the barrel which the original design suffers from.