M14s are 455mm in length. 500mm is around the M16/M24 Length.fuzzywolly said:I doubt the 500mm barrel will work most likely because most 500mm barrels are m14 barrels. M14 hop up chambers have different cut barrels which are not compatible with other AEGs.
So no, the 500mm barrel will not work. I've only seen 500mm barrels for m14s. If you can find a standard AEG barrel that length, than go for it.