First off, a citizen can legally buy as much ammo as they can afford. Now that this is out of the way, anyone buying 180,000 would be a red flag to me unless they are a retailer, it just isn't something a normal person would/can do.
But, with the number of illegals in this country, if the persons purchasing the ammo were clearly ESL (English as a second language) persons, I'd definitely be inclined to believe they probably weren't legal purchasers. This would be the case for anyone who's native language is Spanish, German, French, Russian, Chinese.... We have to be able to use the contextual clues in front of us to help us navigate daily life. Some of these clues are going to be race based by color of skin and by language/accent used. Additionally, the volume of ammunition being purchased would be considered. When trying to work within the confines of what is and isn't legal, all of the facts needs to be considered to help determine if something looks hinky or legit. If the purchaser(s) of that much ammo were middle aged white guys with apparent gang tats, I'd question the purchase as well. But again, given the sheer volume of ammunition these individuals had, a middle aged white guy or a senior aged school marm-ish looking woman would have raised my eye brows as it's so far out of the norm. If a younger to middle aged black, hispanic or Middle Eastern descent male, all of which spoke English with Americanesque accents, came to buy 1-2 thousand rounds of ammo, I wouldn't blink an eye. All of the facts of a situation matter, and that definitely includes race.
That painted the picture beautifully.