Not sticking up for them at all, but typically to buy ammunition you have to be at least of the same minimum age as you would to purchase the firearm that would fire it. I can’t find where FL’s new law specifically addressed ammunition age restrictions, but I’d imagine it’s a CYA move by BPS, since you now have to be 21 to buy longguns there.
By the way, when was the last time any of us actually bought anything from BPS? Their prices are worse than vans... Can’t boycott if you aren’t already a customer.