Madbob
I worked maintenance on the Huey in the Dhofar, Oman troubles in 1973 and can certainly vouch for its sturdiness.
I remember one called out to a woman in labour at sunset. On descent to the village the helicopter took fire, probably from AK47. The pilot, Colin H, decided to cancel the visit and was fired upon as he once again climbed over the mountain edge. At Salalah I helped shut the engine down as the electrics at the centre windscreen had been shot out.
In all I counted 37 entry holes including some through the roof of the cabin area. Colin was lucky that he only caught a ricochet on the collective that broke a finger.
Our machines had the Lycoming T53-X I think we started off at -11 and its only oddity was if it took a round through the exhaust, which did happen, the N2 could become unstable.
As to worrying about taking a hit through the chin bubble, nothing up the front was strong. Even the glass fibre armour plates on the floor and doors were only held on by AN4- bolts and would not necessarily stay in place when hit.
The main blades at that time were made by more than one manufacturer but could take two or three bullet holes without trouble. It would sound like a steam engine coming into Salalah. The repair kits were not very much use on the blades and the patch may come off in one flight or it would last quite a few trips.