Store bought shells vs shipped

[Oconeeguy]

Bought a few boxes 3" Fed HWT #7 over the internet from a store in another state. Every shell rattles a little if shaken, and it looks like a small amount of fine, white sand is in each box of shells (buffer?). Bought a few more boxes at a shop in Augusta. None of those shells rattle.

I suspect the shipment may have caused a little of the buffer, if there is any, to come out of the shells that were shipped to me. Haven't shot any yet.

Anyone notice pattern issues with similar shipped shells ?

[SKFOOTER]

The stores have to have them shipped to them also so I wouldn't see what difference it would make.