My long gone Dad told me that resizing a single chamber gun cartridge wasn't necessary since the chamber sizes the brass to the necessary size, unlike a revolver which has multiple sizes. He also said this is a benefit in minimizing the work hardening of the brass.
Any truth to his advice? The two long guns of his are a 6.5 x 55 Swede Mauser and a .22 Hornet Stevens Walnut Hill falling block single shot. I'll be reloading and shooting these soon.