We had these things called “Commanders call” in The USAF. As I remember they were one every few months in the large auditorium. One of the topics was of the new A-10 with film of the arsenal and capabilities. Since our base was a missle base we didn’t have many planes on our flight line other than stop overs,etc. But once as we took our trucks out to the flight line to unload and load there were 2 A-10s out there. we jumped out of the trucks to examine them. the size of the barrels on the guns were huge, very impressive to a young man of 20. 30 mm I believe.