I recall hearing/reading somewhere that the rim on a .45 Auto Rim is thicker than a normal revolver cartridges rim to compensate for a full moon or half moon clip(s), because the clip(s) require more space in the frame of the revolver.
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Yes, rather thick rim. Guns like the 1917 revolvers had a large gap between cylinder and recoil shield to allow for thickness of the moon clips. The AR cartridge has a thicker rim than most to fill in that gap.
The S&W 25-2 and 625 series (625JM, 625PC, etc.) all will fire .45 ACP with or without clips (half moon, moon, etc.) Apparently S&W decided to lengthen the chamber slightly on the 625s, so that with the normal short firing pin, you can get misfires. I cure that with a longer firing pin. I usually shoot .45 ACP without clips or shoot .45 AR.
The Ruger NMBH in .45 Colt with the .45 ACP cylinder will also shoot .45 ACP without clips. As they come from the factory they wont shoot .45 AR, but it is a very easy conversion on a lathe to allow .45 AR to headspace on the .45 ACP cylinder. I prefer to use .45 AR in mine because it seems to cycle more smoothly than .45 ACP.