[RWD version 1 ] As many others have said Bencorrbeg is a serious scrambling challenge. This track was an attempt to reach it from the south via the Coillte (state-owned) forest with clear public access and parking.
The walk through the forest is easy if tedious. It has magnificent views being under some of the best of the Bens and in full view of the Maumturks to the east.
We took a route through rough cut forest land off the forest road. Unfortunately the shared GPS track lost some detail in places. In part this can happen when ascending extremely steep slopes and the GPS unit's view of the sky is constrained, however the general line we took is visible. The track shows pink because much of it was done at a slow, scrambling pace. Nevertheless there were great and increasing views as we ascended towards the 'Turks and further.
From the top there is a huge view of eastern Twelve Bens. Bencorrbeg is linked to these via the rocky col to Binn an tSaighdiúra

Although we managed to get up via the rocky south side of the east ridge of Bencorrbeg, we found it difficult and so looked around for a route down that was easier and safer.
Many of the slopes around here are convex meaning that from top or bottom it is hard to see whether a scrambling route is actually possible as others have reported on MV for Bencorrbeg. Taking a route you are not sure of is a recipe for getting stuck halfway down a slope. However the route down that we took uses the concave slope shown clearly on the Harvey map which has an unusual surface of quartzite chunks mostly embedded in bog vegetation. Not easy to move through but relatively unexposed and relatively easy to navigate.
Unfortunately it left us on the wrong side of Bencorrbeg from where we had parked necessitating a long contour around the north end of the ridge. We had hoped for the occasional contouring sheep track to help with this. No such luck. A slog until we got back the forest and the forest road.