I would assume(but please check before proceding) that the Circuit Judge can handle more powerful loads than standard 45 Colt loads. So you can probably use the Ruger/TC loads found in reloading manuals. Get a decent jacketed hollow point(Hornady XTP for example) and a slower burning powder (H110/Winchester 296, 2400, Lil Gun, 4227, etc.) and use the starting loads. A 250ish grain bullet at 1,200ish fps is plenty for deer.
But again check to make sure you can use hotter loads in the.