I usually shoot my carry ammo out at the end of the year, but I honestly have never seen ammo go bad. I've shot so many rounds that were older than I am without one single FTF and I have no idea how that ammo was stored for at least half of its life. So even though I do switch to fresh ammo once a year it's more for feel good reasons than bad experiences or actual reports on failures. To switch out ammo more often IMHO would just be more a mental thing and not for REAL reasons - but if it floats your boat, what the heck!