The ammo affected is 2 lots of their M*22* 40gr ammo.
Check it out:
Winchester has released the following notice on their website about some of their .22LR ammo.
The ammo affected is 2 lots of their M*22* 40gr ammo. The issue is that some of the rounds could be double charged. A double charge is one of the worst ammo defects you can experience as it could possibly cause damage to a firearm and/or harm to the shooter or bystanders.
Winchester has determined the above lots of 22 Long Rifle rimfire ammunition may contain double powder charges. Ammunition with double powder charges may subject the shooter or bystanders to a risk of serious personal injury and/or death, or cause firearm damage, rendering the firearm inoperable.