The AGN App is ready! Search "Airgun Nation" in your App store. To compliment this new tech we've assigned the "Threads" Feed & "Dark" Mode. To revert back click HERE.
Try Talon Tunes. I just bought a Superior liner and they had lots of other stuff in stock too. Not sure about the 600mm barrel kit though. Check around, I would think somebody has it in stock. Good luck.