I have a KM4A1 for which the KWA factory swapped out the stock barrel for the CQB barrel in September 2011. It was working well for me for about 1500-2000 rounds, but now the hop up unit "sticks" in the rectangular chamber it slides into- there is no free float. With my primitive camera skills, I've attempted to capture it and circle the offending area in red. The rectangular chamber is no longer rectangular and is askew by about 1mm, resulting in loss of free float. Is there a way for me to correct this without removing the roll pins, gas tube...? I'd have to buy the correct punches and another set of roll pins to do this.
Thanks in advance for your help.