I think the Winkler axes are 5160. I wonder how it compares to S7 in edge holding. A 1-hand rucki pig sticker sounds good to me
They were 5160. Daniel now uses 80CrV2 for almost all his blades. Although I think some of the breaching / rescue axes may be S7 or H13 still, and there are some smaller knives in 3V and CPM 154.
5160, with a non botched heat treat, should perform very similarly to S7. Both are lower to mid carbon steels tha t reach the upper 50's in RC and have a lot of toughness / ductility.