Who takes the time to look at the trades on your gun while your shooting them anyway?
Honestly, pay no mind to anything people say about the internals. It's a G&G, they're crap internals, it's a given. But why care if you wanna upgrade it anyway?
The externals are nice, good plastic body on it, feels like the CA36 series, good feel to it, nicer than TM.
It boasts magazines with the strongest springs I've ever seen, you won't ever have to replace or lube these mags lol
Alright, so in order to get it shooting good you need: (systema everything); piston head, cylinder head, piston, spring guide, hopup rubber.
You need the piston because the stock G&G piston won't take the systema piston head. I only shimmed the bevel gear, it's really the only gear that you need to worry about shimming.
Anyway thats what I have in my UMG and its got fantastic range and accuracy with 310fps (I put a stock CA spring in).