krusty, i don't believe the mg/ffm was noted for it's range or hitting power...hence the main reason it was replaced by the mg 151/15 and subsequently the mg 151/20...on the other hand, weren't the hurricane mk1's produced with wooden frames and fabric covering the fuselage? if it's modelled that way in ah, that would explain some of the low damage from the mg/ffm shells...it's been documented that the explosive shell wasn't as effective against the early hurricanes as it was against the all metal aircraft.
What is "range"? For the MG17s the effective range is really 150 yards. MG/FFm were good out to 400 and more. Yes, the accuracy got worse, the further out. BUT, if you hit you killed the target, whereas the MG17s did not. It was a major step upward, and one the RAF would mimick quickly. The BOB proved one thing: rifle caliber Mgs didn't bring down planes fast enough or at long enough range. All nations would move past this armament at some point.
The wooden vulnerability of the Hurricane is another myth that goes around. I don't think I really believe that one. I think it's possible some rounds went through just making a hole, but then some 20mm rounds in WW2 were solid AP rounds. Some were tracers. Some were duds. Not all exploded. Looking at other wooden planes, 20mms had no problems bringing them down if they landed hits. I tend to think that's more wishful thinking than actual fact.
Regardless, from personal opinion I think the hurricane is a bit tougher than the spitfire1 (in-game, I mean). So I think that's already accounted for.