Me being somewhat of a Encore noob...

about all I can tell you is, it starts about the end of the
chamber, and different contours do need different fore ends.
I've got a heavy taper 24" custom .875 at the muzzle that
works ok with a prohunter, but when I added a standard contour
Bergara, about .725 at the muzzle, had to have another for it.