Hey, probably a trite question but my search didn't really turn up anything on this.

Yesterday, I received an order from Shopper's Vineyard. Of interest to this post, the following were included:

(2) 750ml PVW 20
(1) 750ml VW lot B

I already had one lot B, as well as a PVW 15 from a brick & mortar purchase a couple weeks ago. I noticed that the fill levels on all these bottles were different, with the bottles bought in-person appearing to be more full than those from SV. The PVW 20s both seemed to be the least-filled, followed by the SV lot B.

The store-bought lot B and PVW 15 looked more-filled and both seemed pretty close to the same to each other. None of these were drastic differences, but noticible. Hard to for me to quantify without them in front of me, but it wasn't incredibly major - maybe the difference between the fullest-looking and the least would be a half-inch or so.

My first thought was that perhaps the shipped bottles were upside down for an extended time in transit, and the corks soaked up enough to account for the variations? Or maybe each bottle is not 100% identical, one may be a little larger or a little thicker, and that's making one bottle look a little underfilled compared to another? Or is this a pretty routine difference that just can happen from bottle to bottle?

Anyway, I've got nothing but a head full of questions. Anyone got anything a little more substantial