I couldn't quite find this tomb, it has been swallowed up by a pine plantation. I think a return trip during the winter, hopefully when there is less grass and fern, may help me find the tomb.
To get to the plantation coming from the east (by road), I stopped at the first gate into the right, it has a small security sign on its gate. I followed the track on the map straight up and keep to the right. You will come to a branch to two different pine planations in the distant (this is subject to plantations regrowing), follow the one to the right. Keep following this path about a half km. You will need a GPS to find it from there. Where I searched was above a lip on the hill.
As an aside I did find a complete deers antler but no tomb.
I decided to head over the mountains from Nenagh to Cahir and as I was passing by Kilcommon I decided to look for this tomb again. When I got up to where the plantation used be, euraka, it was gone, they had cut the trees.
The ten digit OS Ref is R9127659984 for anyone that happens to go up here when the trees have grown back.
Its a small tomb (about 1.25m long by 0.5 high by 1m wide) but it does have some interesting features, like all the tombs in the area it is dominated by the Mahurslieve to the North. To the east there is a funny looking artificial ridge built up and to the west a range of hills with a notch in between.