Since it is allowed as your only back-up... I would say that your Remington is the very best choice.
I have shot them side by side with my Walker, 1851', and 1860 and the Remington out penitrated them all with a RB!
And would never leave it at home... I have stories from the 1800's that tell of many grizzlies being killed with the C&B revolver
Penitration on whitetails is very good, with many "pass-threw" shots.
What I notice most when butchering WhiteTales is that there is almost no tissue damage around the hole...so placement is important... heavy bone will trash a RB and send it off of its path....
Some have been misslead to believe that the RB will expand...but I have a jar of recovered round balls from game and can say that not one of them has expanded
...the RB is structurally stable so expansion is not likely from a pistol.
I found that 4FF will give a higher velocity than 3ff (mostly cause more will fit)...and NO it does not cause a dangerous situation, It just puts more powder and less air in your chamber..1000's of balls down the pipe of my Remingtons have proven that.
Pyrodex P acctually give me a high pressure and velocity.
I would choose the Conical because in your application..Weight will=Penitration