Schrade 7cr13 variability!

[trapper12345$]

3 different schrade fixed blades (2 -ph1's with staglon handles . 1-phw with iron wood handles ) all given a 25 degree edge and honed to shaving and paper cutting sharp. The 2 stagalon are 15 years old and the phw is 5 years old. In my cardboard cut test the 2 stagalon 7cr13 blades stay paper cut sharp for approximately 47 to 50 cuts, similar to other 7cr13 and aus 8 that i have tested. The wood handle phw model is 85 to 95 cardboard cuts, similar to some of the aus10, and sanvik 14c28 blades i have previously tested. Can the heat treat be that random in the schrade 7cr steel. all comments appreciated.