Heavier than normal 1st ed team Rocket packs

Recently broke open a 1st edition team rocket booster box and the heavies weighed around 21.5 while the lighter ones were around 21.3. I am guessing maybe moisture? Opened 2 packs at 21.5 and they are fine and got holos then opened one at 21.3 and got a light, but still wondering why they weigh like this. Has anyone had this issue?

Meant to post under “just a question”

@maverick23, Discussing pack weights is typically frowned upon on efour, so you may not get an exact answer. I would just open the ones you want to open and be happy with them. Every box is different.

Yes I know that, but it was more of the lines of how abnormal this is? I plan on opening most of them.