.008 is minuscule on a 2x4, but not in a revolver. Take the gap between cylinder and barrel for instance. Factory spec used to be about .004 to .008. More importantly to this discussion is rear gauge or headspace. The nominal rim thickness for cartridges is .060. The factory min, headspace of gauge is the same .060, max is .070. If you happen to have a revolver that has min headspace and minimum end shake a primer that is any amount high will bind. Most have a bit over the .060 min and some end shake. If you have .060 gauge and .002 end shake the cylinder could move forward .002 and let a little bit of a high primer slide along the recoil shield. Same things apply to cases and primers. Some small variation.

Normally you can probably get a large rifle prime to work in a large revolver. Given enough mainspring, and enough headspace or a minimum height primer or a slightly deep pocket. But, it your gun has minimum headspace, the primer was at max thickness and the cases had minimum depth pockets you might have a problem. All this pllus how much does he change in primers effect pressure etc.

I get it and if push came to shove and there was nothing else avalible, I would use the large pistol primers. But, I have lots of large rifle cases. I will use them there. If I had a lot of large rifle primers and no use for them I would look for a trade and I am sure with a little effort you could find a trade or sell the rifle primes for a small loss and go buy the correct primers.