Sometimes stores like Wally-Mart and Canuck Tire store their inventory in unheated warehouses.This can effect the powder in the shells giving erratic behavior when shooting.I have a 10-22 plus several other 22's and I experience half a dozen missfire to a box sometimes.I usually run them through again and they will go bang.I know the 10-22 is a great little gun but regular cleaning(100-200 rds.) keep them banging and ejecting lickety split.If you have ever found some old ammo that was left out in a building or vehicle over winter it is bound to be iffy when you fire it.I guess thats why you are told to store it in a dry-humidy free area.I know the big chain stores don't care about non-perishable items and it cost money to heat a warehouse in Canada.Thats my story and your welcome to it...