kjw519

I am trying to install the 70085 collapsible stock on my M4 (11713). The recoil spring tube is cut for three positions. The pistol grip went on fine. However when I try to put the stock on it won't rotate to the right. I have tried to follow the Rat Worx video on YouTube (https://www.youtube.com/watch?v=lpkKyPwHxNI), at the 1:30 mark. However, I can't get it to turn to the right after sliding it on at the 45 degree angle. It appears to me that the stock is not initially sliding far enough onto the recoil spring tube, but I'm not sure. When I get it as far as it will go and try to turn to the right it binds and I can't turn it. Any ideas or suggestions? The limited number of videos I've seen about installing this there doesn't seem to be any issues sliding this on and turning it, so I feel that there is something wrong with the stock (or possibly the tube)? Any ideas? The photo is looking into the stock tube. The retainer that retracts when the button is depressed is on the top (it looks slightly off center in the slot to me, but I don't know if that would cause installation problems). The retainer on the right does not retract.