348,
Welcome to HH!
Personally I would not recommend the Weatherby cases for the Encore.
With the head size of the case, it just creates more back thrust, and more flexing of the frame, and case stretch/case head separation possibilities.
Why have a case that you cannot utilize?
Some of my favorite hot-rod cartridges for the Encore would include:
Anything based on the 308 Winchester family included all of the improved versions (not real hot-rods but great cartridges).
Anything based of of the 284 Winchester (Winchester brass)or the 6.5-284 (Lapua brass).
The 06 family and its improved versions.
Personally, I would not go above the 30-06/308 head size in a Encore.