The the CGS guns are uh, boy they're rough. I dunno if it's worth sinking much more time or money into tbh.
Step one, bin/sell the mags. Consider either the Double Eagle Stanags (not the PMAGs those are ass) or the TM Stanags. They should be compatible and are just better made all round.
If it were me though, I'd just get an MWS instead tbh. The CGS isn't much cheaper but misses a lot of the internal parts that make the MWS good. You're not really at the bottom of a curve sadly, the CGS is just ass.