A "high firepower weapons ban"

[SayWut]

26. "fire power" based on ammuniation isn't that simple.

30-06 isn't a caliber, it's a cartridge. In your example 7.62mm or .30 would be the caliber.
Trivial nomenclature, nit-picking, arguing over technicalities? Not really.

.30 caliber ammunition comes in all sizes, loads, muzzle energy; from the relatively weak 7.62x39 (AK-47, 1,810 ft·lbf), and .30 carbine (M1 carbine, 880 ft·lbf), to the .300 Win Mag (4,027 ft·lbf ,avg muzzle energy compared to the 30-06 muzzle energy of 2,900 lbf).

OTOH, there is 7mm ammunition that is just (or more powerful), than .30 caliber/7.62mm).

Point is, using a caliber based standard or measure of "fire power" doesn't accomplish what it sets out to do. Using your reasoning (or what you hope to accomplish), one would have to use the average muzzle energy (bullet weight x muzzle velocity. Note: muzzle velocity can vary due to barrel length, type and amount of powder and even temperature), as the cut-off point.

Another example you use is .44 Magnum (.44 being the caliber).

Even though .45 ACP is just a hair larger in diameter, it has nowhere near the muzzle energy of the .44 magnum. .45 ACP also happens to be one of the most popular cartridges around.

Now, given all those variables, how would "fire power" be determined as to what constitutes a legal firearm if ammunition is taken into consideration?