This was absolutely hilarious to do, and we didn't melt the gun, it's as weak as ever.
ps. I'm quite convinced we were sent a secret prototype by mistake. The soldering inside was so big, and components so heavy, that it was really meant for 12V. It drained the friggin' car battery and stopped! Not a speck of heat. I hooked up a Lithium ion car jump starter and it immediately complained of an overdraw. My poor spare car battery is going to take days to charge up. This was obviously meant to fight aliens. :)
IMPORTANT BATTERY NOTE: Don't use regular alkalines, use the Panasonic high drain alkalines from Dollarama. They are the same as the 12V without the burning.