Hi all,
I had a request to do a detailed pictorial on the disassembly of the Shell Stop. Removal of the Shell Stop is the same for the factory and GG&G model. In fact, the GG&G model is simply a modified factory Shell Stop.
Start out by unloading the weapon and setting the ammuntion away from the work area. Field strip the M4, remove the barrel assembly, bolt carrier and trigger group. The stock may be left on.
This is a view of the inside of the receiver. It shows the placement of the Shell Stop Spring. The spring is a loose fit, so you should note its position before disassembly.