I have several such situations, multiple 243s, 308s, 260s, 30-30s, 32-20, 38-55 and 375s.....etc, etc, etc..........For my lever guns I full length size them all and use the same load in all of them, of the same caliber. For my other CF rifles I have them in MTM boxes marked for which rifle they belong to and I process them as though they were different calibers, never mixing my cases from one rifle to the others in the same cartridge.
I have one interesting anomaly all my 243s have exactly the same headspace. My partial sized cases from my original 243 700 Rem fit every chamber of the 4 or 5, 243s I have, all with a slight bump down on the bolt handle. I always thought this was kinda cool, however they do not use the same loads so they are still kept separate and marked as such.
It doesn't really matter how you do your loading, neck size, partial size, full length size, ammo for every rifle regardless of identical chamberings should be treated as a distinct and separate cartridge. No different than if one was a 308 and the other was a 30-06 and had nothing in common besides bullet dia.
You should also never assume, because you have an outstanding load for a chambering in one rifle, that it will be outstanding in a different rifle of the same chambering or even safe for that matter. Treat every single rifle , even in the same chambering as a separate and distinct firearm, with regards to loading for it, and you will never run into trouble or damage a fine rifle.
I have two mod 86 wins in 33 WCF that will not shoot the same bullet weight (250 gns) to point of aim, one loves the 250 RN Horn, the other shoots it 3 ft high at 100 mtrs and of course does not have enough sight adjustment to bring it to point of aim. The full rifle shoots 200 FTX to point of aim and the light rifle button mag shoots the 250s, same twist barrels, just 2 different rifles I guess.