I was so very disappointed to learn that Bronson, playing Paul Kersey in Death Wish, used a 32 caliber nickel plated Colt Police Positive revolver with a 4-inch barrel.
I've always considered the 32 caliber a very weak weapon.
He used lots of different guns throughout that series, IIRC. I was thinking of the terrible Death Wish 6 where he had a .475 Wildey Magnum delivered to fight off the thugs.
I guess John Browning was more of an inventor than expert at self defense but his favorite gun was the little FN model 1900 or maybe the similar Colt.