Oddball deal. I'd probably go ahead and shoot, although not necessarily expecting a tight group.
You could pull a bullet, I guess, to see if the powder charge looks to be about right for quantity. Or weigh it.
If a trip back to Dick's is no big deal, you could talk to them to see if others have had this sort of deal.
As a last resort, I guess you could call Remington, telling the first live person you get on the phone that it's a safety concern.
Hope you've kept the receipt...
You're from BATFE? Come right in! I use all your fine products!