From the rear of action to loading its totally split in two halves vertically right through the dovetail. Weak part max 7mm thick which will affect the lateral shift, no beefy good fit rail will sort that.
It is what it is an attempt to produce a cheap rifle, if the action was one piece or bolted together from the front, it could be a cost effective building block.
ie most aluminium German stocks are in excess of £800 to buy, some you have to buy with them fitted just to get the action so effectively junking £800.
With the AR20 its no great shake junking the backend, forend, tatting with trigger, reworking the alum extrusion it all can be done at a suitable upgrade time throwing little dosh away in the process.
Some things cant cure, well you can but will exceed the dearest rifle produced about 6 times dearer.