Good luck on your hunt preparations.
My 570 Ranger quit on me yesterday also. If it quits raining tomorrow I plan to pull the battery and check it out, clean the posts and charge it. With a little luck that will have it running again.
What load are you shooting in your Optima?
Mine works well with about anything I have tried on the first shot. BuckHorn 209 is by far the cleanest powder, and reloading several times is not a problem with it. It would be better if it were cheaper however. I have been running Harvester sabots and 250 grain Colt 45 Bullets in mine.