There are plenty of factory accessory barrels for both the T/C Contender and Encore but if you want a cartridge not offered by T/C then you will need to order a custom barrel.
Custom barrels are really nice because you get to chose what caliber, barrel length, barrel profile, barrel finish, sights, scope mount and muzzle brakes. Plus the quality and accuracy are much higher than T/C factory barrels in my experience.
I have owned many custom T/C Encore barrels from 2 custom gunsmith shops… Match Grade Machine and SSK Industries. Both companies make excellent barrels with many options. However I prefer Match Grade Machine. Their prices are better and offer the same quality. I have owned about 6 difference custom barrels from Match Grade Machine or MGM. The caliber selection is huge. I had one made in the .470 Capstick.