Well, I have read annecdotes from P-38 pilots talking about overheating the guns. I don't know if that's an airframe specific problem, since all the guns are located closely in a tightly cowled nose or not. I guess most of the U.S. planes had at least 3 guns packed together in each wing. I would assume that the airflow has a huge impact since all 18 cylinders of the engine are being cooled by the same air--but I don't think the guns had baffling, and certainly didn't have intakes. So, that theory may be a wash. I think that the G-Loaded feeding and extraction would probably be a bigger factor. Those feed trays can be a bit sensitive...
