Nkrumah Was Right
Superstar
Why didn't they just reverse engineer those guns and produce their own. One thing that always puzzles me about when Africans first met the Europeans is their appraoach. When the Japanese first met the Europeans they set up "Rangaku" throughout their country to reverse engineer a lot of the goods that Europeans were giving them. The japanese were able to reverse engineer the first guns that Europeans gave them to the point where they started making theeir own. This is actually why Europeans started trading "expertise" instead down the line. They couldnt just sell trinkets like guns to the Japanese anymore. This would all lead to the japanese basically industrializing in basically 30 years (1860 to 1890). Now why did Africans just trade without thought? Native Americans and other indiginous groups did the same.... Just traded with the Euros yet didnt reverse engineer.
The only exception to this I think was Idris Alooma's empire. They were getting close to producing their own guns but their arab "brothers in islam" attacked them before they could perfect it.
Africans were able to create their own muskets, but not rifles. They didn't have the tools to make rifles.