Can't definitely tell but it is a guess from their age, dress and demeanor. The guys I'm seeing come in separately, are in their 50's and 60's (except for one young guy), are friendly and relaxed. Some are looking for 9's, some for 22's, some for 223's.
Apparently there were four or five guys who only showed up as a group and only on days ammo was delivered. The speculation was they knew when ammo was being delivered. One of them apparently indicated they were re-selling. I don't think he ever refused to sell to them but when he asked them to leave some for the other guys they apparently got surly.
The managers somehow changed the unloading to limit who knew when ammo is in a shipment. Since then I've not heard about that group.
I'm not a high volume shooter so I'll pass on the next round of 223's, but 9's and 22's are still on my want list.