If i understand correctly, the Winchester Apex is/was made by CVA. It was/is similar to the TC Omega. The breech plug is the same as the breech plug in the old Optima, and Accura. If this is true, i have modified many many of these breech plugs, so owners could reliably shoot Blackhorn in their rifles.
Here is
one way to modify the breech plug.
If you cannot, or don't wish to do the work yourself, i can do the work in exchange for dinero.