Smoke/Illumination depletion?

[Blackcloud6]

When using the optional smoke or illumination rule, if the activated firing unit fail the roll to get the ammunition, is the ammunition considered expended?  The rule is silent on this but alludes that it is expended because the procedure starts with "For each unit or artillery increment firing...," which implies to me the unit fires and thus the ammunition is expended.

What say you?

[joe_oppenheimer]

I've always played that it's expended.

[cjsiam]

I agree it is expended----the smoke shells fired were not concentrated enough to impact game, no smoke counter, but shots were taken.