445 battery/ driver comparason

for whatever reason, your other build isn't getting the full current, because I believe the beam wii actually change shape as you increase the current and more modes start resonating.

Keep in mind that CR123 nom. V is 3V, so 6V total. You might want to consider moving up to Li-Ion 16340 cells. Only brand I can recommend is AW, although if Redilast or Callie's makes 16340s, those would probably be fine too. I did see in the mohgasm sales thread that one user reported that old (probably no-name brand, i.e. ____fire) 16340s he was using couldn't supply the current, but the IMR16340s he got from AW did just fine.
http://laserpointerforums.com/f39/fs-mohgasm-linear-drivers-68378-3.html#post994956

Get protected cells if you can. Those have circuitry, like a circuit breaker, that cuts out if you draw too much current or if you drain the cell to "empty." The "breaker" resets when you put it back on the charger. Best not to rely on it as a sign to charge your cells, but if you do hit the low voltage cutout, no biggie, whereas with a bare Li-Ion cell, if you hit the low voltage threshold, it will still keep discharging until it breaks itself or burns itself up. And you'd never know, and it may pop when you try to revive it. So, yeah.