I have one, and it sucked, it was more of a barrel launcher. I use servo recoil in my tanks.
the HL recoil is so dissapointing. It works backwards, it slowly comes back and then pops forward, on mine the barrel would fly out after the second firing, so i disconnected it.
imho, best thing to do is use the mount, modify and chop and add a servo that runs on a good aftermarket electronics system.
sorry, not any help I know...