I also feed my 1903 Colt 32 cal., Fiocchi 73 grain FMJ. I never have any issues with it. As for self defense round, I've had the best luck with Glaser Power Ball. In addition I've used Buffalo Bore Ammunition 32 ACP +P 75 Grain Hardcast Flat Nose. Works fine but I think it's too powerful it such an old gun.(It works great in my Berretta Mod. 70, 3 inch bbl).