On the one hand, this demonstrates the main problem with mixing steel and aluminum. Real Russian AK trunnions are forged with a little bit of Stalin’s blood to ensure they are the toughest guns ever made and it’s not really fair to install an aluminum rail that’s only got a quarter-inch of purchase on a single hinge and expect it to hold up.
On the other hand this not-very-extreme test neatly exploits the drawback of using aluminum for a railed dust cover. For that purpose there’s always the steel Parabellum Armament AKARS which is a whole lot tougher with extended mounting points. Hopefully Texas Weapon Systems will address this issue with a steel rear sight adapter that wraps around the trunnion.
In any case this is a pretty unusual situation, and not likely to happen outside of deliberate abuse.
If your AK doesn’t have a side rail — what many would argue is the ideal way to put a scope on this type of rifle — check out what Parabellum Armament has to offer. They’ve got a lot of nifty AK stuff.