the isolant coating on the rotor's windings would probably melt down and cause a short and that is if the gear havent melted yet
i was thinking i have a crosman mini mp5 ... mabe i'll try to kill it
i've actually ran it on a 12v 7ah battery and the motor fried, but i replaced it! maybe i'll try with a 7.4v 3600mah lipo this time