When you have 2 or more arms, that use the caliber, BUT operate at different levels (ie. bolt action vs. gas operated; old Colt vs Ruger Blackhawk) IF you load to MAX for one, but same load is WAY OVER MAX for the other; make them easily identifiable! Max level hunting bullet in bolt action hunting loads, but AK gets FMJ ONLY. Even in the same gun, MY .30-30 hunting loads are in Winchester brass and JSP, but plunking loads, for 9yo grandson, are Federal brass and a RED powder-coated bullet. .45C hunting loads are black powder coated, cowboy action loads are red. .357 loads are lime green hunting loads 158gr, red self defense loads 125gr and purple cowboy loads 102gr. I have 1 bullet, red powder coated 115gr .308 plunking bullet that is loaded in .30-06, .30-30, and .30Carbine. Above all, keep good records.