If the lot number inside the box flap is different on each box, then something else is different too, even if you can't see what it is!!
That's another thing that's strange, is that both boxes of ammo had no lot numbers on them, I checked every inside surface of each box.
Some shops will use the factory ammo themselves and then reload it with inferior materials and sell it as brand new. It's not common but one shop in my town was caught doing it more than once.
I bought the ammo at Gander Mountain, so I doubt this could be the case. It's not very likely that they'd take the time to sell reloads in Winchester boxes.
I guess I'll see if there is any difference between the two at the range. I wish my chronograph was still functional (took a sabot to the faceplate the last time out), as I'd be curious to see if the loads are the same.
Mike