RE: American pioneer powder
Similar data can be found by comparing it to Pyrodex & Blackpowder loads. That will get you close with APP.
Congrats on your new Encore! Buy Harvester plastic sabots for it (50-pks) because T/C bores are tight... even with their own packaged bullets. Swap the packaged bullet sabots with the Harvesters. If you can find the new ribbed Harvesters, please buy those & do a report here on their accuracy, quality & ease of loading.