It would be difficult if not impossible to know what that was in your gun without actually having your gun. Regardless of what the Sierra book said, it would have little if nothing to do with how that bullet can be loaded in your Encore....maybe a baseline but definitely not optimum.
Take an empty case pinch the neck with a pair of pliers just enough to hold a bullet snug. Push a bullet in the neck and chamber/close the gun. Measure the dummy, do it a few times...this will give you the length to the lands. Once you are ready to start loading real ammo, you now have a reference where the bullet sits 'to the lands' work back from there. Most guys will say you need a minimum of .020" back of the lands and in your Encore you don't have to worry about magazines length. JMHO based on doing this a few hundred times.
