Using the cannon with the central external fuel tank?

[lj0076]

I read on Wiki that using the deck cannon was not possible with the under-hull auxiliary tank:

"Original production MiG-29 aircraft cannot fire the cannon when carrying a centerline fuel tank as it blocks the shell ejection port. This was corrected in the MiG-29S and later versions"

Is that true or not? I know that there is a hole through the tank to vent the gases from the APU, but this is the first time I've heard of this restriction... 

[AeriaGloria]

Yes, it’s in the manual by ED. You can try it yourself