Nowadays you can get replica firearms that looks and feels exactly like the real thing as well as having the ability to load rounds and cycle(/rotate the drum on revolvers) but they don't actually shoot anything(There's no pin, so you can't fire live rounds with it)
There's also a few companies making airsoft weapons that use cartridges that's individually filled with gas as opposed to a magazine filled with gas. This way the gun actually functions like a real firearm, cycles and ejects cartridges that looks real. I believe the blowback on these are weaker but in theory(and I haven't tried this) you could obstruct the barrel and leave the cartridges empty to get a realistic effect. As you would when you need a real gun to cycle when firing blanks.
In my military days I never fired blanks with a revolver but I assume they're used because they don't want to add muzzle flash and smoke in post? And without a BFA there is virtually no recoil, so the only reason I can fathom is to avoid adding this in post.
But for semi automatic/automatic weapons they have to add this in post because of the BFA and this seems to work pretty well? So why isn't it better to use revolvers that doesn't actually fire anything(And add muzzle flash/smoke in post) as opposed to the clearly unsafe option of using a real revolver with blank
