Need a photo's

On the charging handle, The 5  areas being,

The locking hook on the handle ,which should be under strong spring tension, and the hook touching the side of the charging handle.
The bottom of the charging handle U slot, which should have no rub marks, nor impact marks of the back of the key tagging the back of the U slot by the handle.
On the front section where the key passes through it, and should be no binding marks.
The bottom section of the front tab below the hole that the key goes through, and the part that pulls the carrier back via the front flat just in front of the key on the carrier

ON the upper receiver, need to see the locking tab for the handle hook with the handle removed.

Bluntly, the only contact that the charging handle should have with any part beside the upper receiver slot and tab itself, is the bottom of the front tab that pulls the carrier back via the ledge on the carrier just in front of the key.  Also, this contact should be only to the back wall of the carrier ledge, and not a wegde between the bottom of the charging handle tab, and the top of the carrier.



Also, pull all the way back on the charging handle and make sure that the face of the bolt does not retract back past the back edge of the ejection port window.  The face of the bolt should stop about 1/4" to 1/8" in front of the back of ejection port window.  If the bolt face is allowed to retract back past the back edge of the window, then the back of the carrier key will either slam off the back of the charging U slot if a touch out of spec, or into the tube thread ring to crack the lower receiver instead.


As for the rig, looks good, but will always be more of a fan of the fold over stocks on the Zm weapon rigs instead.
The fold over stocks allow for a tighter package for concealed carry, and when you need to use the stock, quickly folds into place with the needed LOP set when you break leather from the start. The down side to a telescoping stock on breaking leather, it takes a longer extra movement to get the stock extended instead.  Plus, we at talking about rigs that are only useful in a phone booth fire fight really, so we you need to use it, it pretty much in full auto bursting instead (yes, miss the days when you could just form 4 the rig as a MG to use the short barrel, instead of having to play the SBR $200 tax stamp game instead).