nope tried that, even on the larger M240B ammo box the 12oz sticks out by about 1.5"

The 12oz however will fit in the INOKATSU with a little persuasion but it's a bitch to take out, you literally have to dismantle the whole rear end of teh LMG

Not sure how big the box is, but how bout a 13cui tank?
edit: nvm

The ammo box is a standard 7.62 box but the feeding mechanism will take up 3/4 of the space you got if not more so realisticly you don't have a lot to work with unless you are willing to sacrifice ammo space

The 249 boxes only have room for a 9.6v large battery underneath
But for the size of tank you COULD conceal on an LMG, I don't think it would last long enough to warrant having it there lol

I was more thinking along the lines TC was with it between the para stock tubes