I have one rifle, I have fought with it for years, I found the issue after I had bought it, the sneaky little devil
... figured I'd see what the general consensus is on how to fix this issue, before I unleash my inner retard on it...
This is a representation of the offending part.. the one in question is a Chinese. (sure, laugh
like you never had anything broke thats stamped.. Made in China)
The lever has broken away or stripped from the shaft that rotates in the rear sight housing, this is the same shaft locks the gas tube in place. Only with this particular one, the shaft will not rotate when the lever is flipped upwards. I can get it apart with some fiddling with a small screw driver, going back together is.....well special and requires a few highly choice words.
I can braze or silver solder the lever to the shaft, making them one piece, I even considered epoxy. Using the brazing/silver solder it wont look right given the goldish/silver material and it most likely won't reblue, epoxy, I'm not fond of, usually it would hold one time, then fall away. Welding was possibly another option I considered for a hot minute...
Also... I have no idea on what the heat involved in brazing/soldering/welding would do to these small parts, they are not overly critical high stress points, so there may be no effect, short of maybe some metal temper changes and maybe some major ugly discoloration in the general area from heat, up to and including the rear sight base.
Finding another lever and shaft crossed my mind...but then it would be used, not really a problem, the issue is the opposite side is swaged....expanded to hold it in the rear sight base, yet allow shaft rotation... swaging the same metal twice if I found a used one, I would imagine might not work out well as the metal is now weakened, from being swaged once originally, then removed and reinstalled a second time.. I think it would be a crap shoot if it were going to hold.
I guess if I were going that far as to replace it..just braze the part while its out and reinstall it.
I've looked for answers some myself in the past, so it must not be a very common issue, as I couldn't find much of anything on the take down lever breaking or stripping away from the shaft.