Thought I'd just give you guys a quick little excerpt. I was lucky enough to find it off Wikipedia, but it's the same as in my book, so it's reliable.
Check it out.
"On my first combat, the 9 of July, I attacked the leader of a Squadriglia of Falcos, while Flt Lt George Burges attacked a S.79 bomber. When I shot the CR.42 at a range of 100 yards, he did a flick-roll and went spinning down. I found myself engaged in dogfighting with the remaining CR.42s. This went down to about 10,000 ft; by then I had used up all my ammunition without much success, although I am convinced I got quite a few strikes on the leader in the initial combat. I realized pretty quickly that dogfighting with biplanes was just not on. They were so manoeuvrable that it was very difficult to get in a shot, and I had to keep diving and turning to keep myself from being shot down. George had by this time disappeared so I stuck my nose down and, with full throttle, was very thankful to get out of the way."
-Plt Off Jock Barber
Just an example of the Fiat CR.42 in action.
Also, I'm going to say that at Medium altitudes, the Macchi MC.202 could take on the Spitfire Mk.V in a successful dogfight. I'll try and find that account as well.