Gorgeous revolver and superb target. With shooting like that, you should have no problem hitting a deer.
Have you considered a heavier bullet and load? The beauty of a 45 ACP revolver is the ease with which you can load SWC's. Years ago I loaded commercially cast 255 gr. SWC's in my Colt Gov't model and not only did a healthy charge of Blue Dot run them in the 950 fps range, the load was extremely accurate.
Let us know if you get a deer.
35WN