Bedbug, what you need is .32 S&W, and not .32 S&W long nor .32 Colt. In the early years of breech loading it seems that Colt and S&W developed some very similar but not quite interchangeable cartridges. Colt's line of cartridges in .32, .38 and .44 calibers were first produced for cartridge conversions of Colt cap & ball revolvers. They all used "heeled" bullets, where the cartridge case diameter is the same as the forward portion of the bullet with just a short "heel" of the bullet being reduced diameter to fit inside the case, the way .22 rimfires are still made. All of the "Colt" line of cartridges were obsolete and about gone until the cowboy shooters got into them.
Anywhoo, I got my .32 S&W ammo from Graf & Sons. They had both Winchester and Magtech brands but I just checked online and they are out of stock. Midway also lists the .32 S&W in Winchester, Remington and Magtech brands but are also out of stock except for Winchester black powder blanks. I do have some Magtech loads left and I have reloading dies but I'm really not much interested in shooting that little belly gun, which is why I still have ammo left. You pop off a few rounds and say "yep, it goes bang" but you can't hit anything past 10 feet and I soon became bored with it. Besides, my wife saw the little H&R and decided it should be her gun and I had no reason to argue the point. I originally bought it as one of four "Saturday Night Specials" which I intended to make into a wall hanging but never got "aroundtooit". The other three are all break tops but I sure like the solid frame a lot better since it is still tight. Fast reloading is superfluous in a pocket pistol anyway. But .32 S&W is what you need and Midway does list it as ".32 S&W short".
As an after thought I checked Natchez Shooters Suply and they have both Aguila and Remington in stock.
http://www.natchezss.com/ammo.cfm?contentID=ammoGroup&ammoGroup=2&searchBy=size&ammoSize=250