Bullet Diameter
With all due respect to 1911user, all modern (post WW-II) .45 Colts have .451 -- .452" bores. They WILL shoot lower pressure loads with .454" bullets, but frequently excessive leading results.
A few years back, I bought a nice Colt New Service of 1920s vintage, chambered in .45 Colt. It wouldn't reliably stay on cowboy hat at 25 yards using a favorite handload with LSWCs sized .452. When I tried some old Remington factory loads, though, groups improved dramatically. It appears that the 250 gr lead flat point hollow based bullets slugged out to fill the .454" barrel nicely. I special ordered some 250 gr LSWC bullets, sized .454" and they performed quite well, until I let a shooting buddy talk me out of the revolver.
In answer to Bandito01's original question: Yes, they'll do, with reservations.
My early handloading efforts with .45 Colt were done with .45 ACP dies. The old CH dies set had a gentle roll crimp, and I was using an old Lyman carbide size die. It worked well, but I didn't like readjusting the dies when i switched back and forth to .45 ACP. My revolver was a Second Generation Colt SAA and it did fine with 230 RNL and the heavier ~270 LSWC from a Lyman/Ideal 454424 mould, sized to .452". I later obtained a proper set of RCBS .45 Colt dies.
I've never heard of an autoloader in .45 Colt - - I really think the gain over the proper .45 ACP would be minimal. I've had three SAAs in .45 Colt, the New Service mentioned earlier, a Second Model Hand Ejector, a Model 28 conversion to .45 Colt, and old and new model Ruger Blackhawks. My only current .45 Colt caliber revolver is a Smith Mountain Gun. All have given good service. With all due respect to Mr. Venturino, I like the .45C cartridge for heavier duty than .45 ACP. I use the heavier LSWC bullets with Unique or H. Universal. It is an excellent cartridge for whitetail deer, wild pigs, and other sporting uses, but I don't try to make it into a .44 mag or .454 Casul.
The Mountain Gun does very well in IDPA or "Tactical Revolver" matches with a 230 LRN bullet over 231 powder.
The compactness and rapid handling of the .45 ACP in an autoloader make it my choice for "social use," but the .45 Colt would certainly serve if I didn't have the autoloader platforms.
Best,
Johnny