Re: .22LR keyhole??
I've never seen a .22lr subsonic round in 40 grains ever keyhole a target from 25 to 250 yards. However, I do understand that this can happen with the 60 grain .22lr SS Aguila as the rifling twist is not correct for this round in most (if not all) factory stocked .22lr barrels. Not sure what twist is required for the keyhole "not" to happen, but I bet someone will be along to let us know.