You're probably wise to keep things simple, though properly stored ammunition can last a very long time.
Simplicity notwithstanding, when it comes to new guns and different chamberings...I've got the morals of a crackwhore. I even handload wildcat cartridges.
I’m about 400 rounds through a 1000 round box of .303 British that was manufactured in 1918 and all of them have fired fine. Cleaning after pumping some of those fulminate primered cartridges through the old war stick is an exercise though...