Which mags compatible with a G&G M4?

[ForensicShoe]

Pretty simple question.

Just picked up a G&G GR16 M4 so now I need some spare magazines for it. Obviously the G&G M4 mags are possibly the best option to go for but I was wondering if any other types of magazine are compatible?

Cheers.

 

[Liam Porter]

My Classic Army mid caps fit perfectly in my mates G&G M4, so does my G&P Mid cap, although it's a crap mag in any gun.

 

[Sike]

ive got the King Arms mid cap box of 5, and they feed fine