It should probably be mentioned that the 300 gr loads may shoot very high. This may not make a difference at close range for protection, but I like to have a revolver sighted to POA. This could be very simple if you have one that takes replaceable front sights.

Back when J.D. Jones came out with his 310 gr bullet, I ordered some. With his recommended load in my 6 inch M29 it hit a full 18 inches high at 25 yards. Also shot into 1 inch groups at that range.

For protection, I would prefer a flat nosed cast or soft point jacketed. Chances are you will have to get the skull. Norma used to make a steel jacketed soft point that would work if you could find some.

For factory ammo, I would go with the 255 gr cast Buffalo Bore.