We have modified the “carry carbine/pistol ammo in magazines” rule for 2019. This is the new rule for 2019:
For the carbine and pistols, each of these weapons must have at least 3 magazines loaded at all times (unless depleted of the rest of your ammo at the end of the event). At least one loaded magazine for each must be accessible without digging into the rucksack.
There is no requirement that “rifle” ammo be stored in magazines.