Has anyone shot the FPB's in an encore yet?
Yes.
If so how did they shoot and load? (is the T/C bore too tight for them?)
They shoot ok with 120 grains of Goex Pinnacle in my Encore. Groups are 2-3" at 100 yards. Groups would have probably been better if I had really tried for accuracy. The Encore bore is not too tight for the FPB bullet.
They loaded easily in my Encore barrel. The QLA really helps a lot with these bullets. They are much harder to load in a gun that does not have a QLA.
Did you use them with pellets or loose powder?
I use Goex Pinnacle powder.
I have killed several big hogs with my Encore and the 350 grain FPB bullet. All have been bang flops or near bang flops. One of those hogs field dressed 212 pounds, another 238 pounds. IME a big hog is about as hard to kill as a black bear.
Good luck on your bear hunt.