The 357 Maximum or 44 Rem Mag would be a good choice but accuracy will be limited to 100 -150 yards. Probably all you'll ever need anyways. Check with Match Grade Machine "aka MGM" for a barrel for your Encore. You won't be disapointed! They should be able to make you a barrel for any caliber you need at a fair price. If you go with the Shilen select match barrel they offer you'll pay a little more. Just around $490.00 for a match grade barrel and a new caliber is well worth it, $50.00 more for a stainless barrel.