Go here if you missed Part 1

     In review, my working theory of Buster science (with some edits for fluidity and compactness) is as follows:

Rockman's Rock Buster is weapon able to produce solar bullet projectiles contingent there is solar energy in his environment that can be channeled in from the solar panel on his helmet. Thus, it presents the illusion of a weapon of infinite ammunition. This system has no connection to his other energy systems, thus Rockman is able to attack regardless of his life energy or special arms energy supply.

     While this theory explains "infinite ammo" as well as a purpose for the solar panel, it still leaves a few potential questions here and there. Fortunately since this is all theory, we are free to amend and change them as necessary. So let's see what gaps need addressing to.

Infinite Power, Just For Shooting?

    Something to consider, if there is so much energy for solar bullets ready to harness, why can't Rockman use it to restore his life energy or special weapons energy? While the original theory already postulates that the Rock Buster energy system and the life/weapon energy system would be separate circuits, it doesn't at all explain WHY one wouldn't link an "infinite" energy supply to the others.

     But my response to this would be that they sorta ALREADY DID. This answer of mine actually requires us to look at X, Rockman's generational sucessor. If we are to assume that structural designs from the original Rockman were in fact carried over to X, it is possible to assume that X's helmet has solar panels similar to Rockman's, and that the X buster has "limitless energy for ammo" just like Rockman's sidearm.

    Interestingly enough, throughout the X series, X receives a number enhancement parts associated to the head or helmet that all relate to sourcing seemingly limitless energy for other things. The head chip in X3 allows for infinite life energy gains, which can return him to full health and charged sub tanks. X4 introduced two helmets that lets X fire normal special weapons endlessly. I suspect that these upgrades are in fact energy converters, which would allow the external solar energy that normally goes to infinite solar bullets to be transformed into something that can be use for life and special weapon energy. The fact these are all hard to gain enhancements suggests that such a converter is complicated technology that's difficult to build and/or maintain.

Battling with Forgotten Head Gear

    Hasn't Rockman fought without his helmet before? For over ten years, there was never any depictions of Rockman firing without his helmet. But then came Rockman 4 Complete Works in 1999, a PSX port of original Rockman 4 which actually has a "secret" no helmet mode. Although technically a secret only accessible via a code, the game itself reveals this mode and the code for access after meeting a game achievement. This code gets repeated in 5 and 6's Complete Works releases. Almost a decade later, Rockman 9 and 10 would also appear with a "hairstyle book" item that allows players to have Rockman to fight with no helmet as well.

     As the theory stands, no helmet means no solar panel, and no solar panel means no sourcer for ammo. Yet in all those games, Rockman can be seen firing happily anyways. What if I tell you there's a possible substitute for the helmet's solar panels which would allow Rock to happily keep firing? And we see it in action at the same time we first saw Rockman launched into battle headgear-less?

    When playing Rockman Complete Works 4~6, an interesting phenomena occurs when Rockman prepares a Rock Buster charge shot when running around with no helmet: His hair starts lighting up and flashing in synchronicity with his body armor, just like how his helmet would. If we were to assume that Rockman's hair was just a prop for his human looks like his face, there would be no reason for it to be showing off energy in that fashion. So maybe Rockman's head of hair are in fact an elaborate optic fiber solar energy collection system. Following this train of though, it would make sense that Rockman needs solar panels installed on his helmet, since the helmet needed for extra protection from physical impacts would unfortunately block those fibers from being useful. (Yeah I know, Ockham's razor, it's probably a lazy sprite layer thing, but they could of done it differently, and you are ruining my geeking rhythm here!)

     So is everything satisfied for a good solid theory? Not quite since I can think of at least one more glaring possible problem for the hypothesis. And a comment feedback from ol'LBD makes for something I hadn't thought of but is worth looking over as well. But I'm a bit exhausted from the writing thus far, so let's continue this chat in a future Part 3. Keep those comments coming in, a good theory doesn't come about without some peer review.