Death to the false Emprah?
IMMA CHARGING MAH PSYFLEMAN--- no wait.
Actually, there is a quite reasonable explanation. BT ammo requires no
feeds, because it is not stored anywhere on the 'Mech
. It is simply stored in a "pocket dimension" instead (as there is NO WAI the missile reloads will fit the missile racks, either, and NO WAI a cannon that has a diameter larger than a 'Mech's limb can have any reloads anywhere), each pocket dimension being a separate reality existing between the superstrings of our regular 11-dimensional multiverse, and the handwavium generators used to maintain these pocket dimensions are placed in the "critical slots" anywhere on a 'Mech. When you pull ammo from the "bin", ammo is actually teleported from the relevant "pocket dimension" directly to the weapon, or rather, the generator creates a stable non-singularity wormhole between the weapon and the pocket dimension and creates the illusion of gravity so that ammo will simply "fall" from the pocket dimension directly into the chamber. "Ammo explosions" are not actually ammo exploding, but the aforementioned generators exploding, and/or the pocket dimensions collapsing (comparable to the evaporation of a small black hole, which tends to produce a lot of oomph) and/or ammo as a result "falling" from the pocket universe into the real universe and exploding, too.
I hope you understood what I tried to explain. The film UltraViolet
somehow managed to explain much
more fluently and concisely a similar concept, namely how the eponymous protagonist was able to carry with her a veritable arsenal of weapons without them being visible, always dropping a fresh weapon into her hand from the "pocket dimension" or whatever it was called when required. I was actually too busy watching Ms. Jovovich's derriere to pay any attention to such trivialities. Correction, am too busy every time I watch the film again. The Director's Cut (haven't seen Theatrical Cut, but folks say it's terribad compared to DC) is actually pretty baws (for the aforementioned reason, and no, not the pocket dimension).
Then again, a 100-ton 15 metres tall walking robot makes no sense to begin with from either technical or tactical point of view...