Note: Not for use in the Encore when running at bolt rig pressures, but I really like some of my big boys.
Some of these are not big rifle calibers, but they deliver plenty of punch at long distances and at short.
My two favs are my 7mm Dakota and my 338 Lapau Improve (338AX).
Both are in XP-100's.
I also have WSM's and a SAUM, but would never recommend them for a Encore.
2700 fps with a 300 grain bullet with a about 100 grains of Retumbo can be a handful, but it still may not make (big bore class for some)