... but neither am I too fond of revealing a HIP gun just to find out it never had that ammo in the 1st place.
Hm, IMHO this is a non-problem. As you note yourself it is possible to make the TH DR prior to revealing the Gun. I never handled it differently. I would announce something like: "My HIP gun is attempting an APCR shot on this tank of yours." If there's no APCR, then the position of the HIP gun is not revealed at all (Bonus question, though: Would it if it rolled boxcars? No APCR, no shot taken, but gun malfed...). The opponent would merely know that the HIP Gun is (likely) in LOS
somewhere. Given the circumstances, he might make good or bad guesses about the Gun's position.
I have even heard about the following ruse:
With some foreboding, you drive your tank towards that dark and menacing patch of woods. The gunner has been mumbling something about a bad dream last night and was very reluctant, not to say fearful to enter the tank this morning. Into the heavy silence, you hear the reverberant voice of your opponent announce: "I will fire at you with my ATG using
APCR..." The last word echoes in your mind as your panic rises.
With dark laughter, your opponent shakes his dice and rolls - above 4... Phew, no APCR!
You might survive a frontal hit with normal AP with a bit of luck, but if you continue on and receive a side hit, you are toast. All the while your Gunner is cursing and repeating: "TOLD you so! Didn't I?" At least, you have found out that this route is unsafe so you turn left and scurry behind some building out of LOS to take the longer detour. It will cost you an extra turn, but at least you will remain alive.
So you think...
As you pull around the other way, even going CE - feeling safe - to get that road bonus, the last what you see is a gunflash from your left flank. Instants later everything goes black...
But the only enemy ATG that attempted an APCR shot on you can
impossibly see this spot where is now to be a burning wreck of your precious tank as you point out to your opponent.
With a sauronic smile he says: "I must have
overlooked the obvious at first when estimating LOS. [Chuckle] To be honest, I was hoping for not having APCR and retaining HIP, that way
making you believe my ATG would be situated in the area of those dark menacing woods. My intention was to scare you away from there, to take the other path. Which you obligingly did and just drove into the crosshairs of my real gun position. I paid for this ruse by consuming my Special Ammo. You paid for it with your tank.
von Marwitz