[Styrak]

The problem is that cheaper brands....CYMA/JG/etc have looser tolerances and can be horrible to get back together. Common issues are the anti-reversal latch doesn't stay in place, the trigger doesn't stay in place, the piston/cylinder/spring combo won't stay in place very well. However CYMA and JG can be excellent performing mechboxes otherwise.

However for example a bunch of G&G and King Arms mechboxes I've opened up, and when you put them back together, everything just stays in place by itself (or only takes one finger on the cylinder)