I made a couple of inquiries about Congo and Gabon

Gabon almost not possible, not to be considered as only a couple of high level guys could be allowed, courtesy of the president Omar Bongo.

Congo : almost everybody is hunting to get bushmeat. Very few is let to a foreign hunter. Moreover, the foreign hunter has to hunt in link with locals.

Chasse libre in Cameroon is very tricky, the loggers building logging road all over the country, what make poaching easier.
Chasse libre in Burkina Faso (there is no jungle in Burkina) is allowed in a few communal areas. As many commercial hunting outfits are deprived of game, I let You imagine what remains in not controlled communal areas.
good luck

NB : jungle hunts are possible with registered outfitters in Cameroon and CAR.