They should assume that 96% of their "customers" are filming them for an exposé.
Yep.
"No sir/ma'am, we don't carry any assault rifles, since assault rifles must be capable of fully-automatic fire per the US Army's own definitions, and have already been HEAVILY regulated since 1934 and the onerous restrictions further tightened in 1986. You may be able to head down to your local PD, army base or armory and ask to see one in action.
Following up on that, we also do not carry any 'military grade' firearms, since any rifle not capable of fully-automatic fire would never be issued to our young servicemen.
What we DO have are sporting rifles, which are semi-automatic and function identically to millions of pistols and revolvers owned by US Citizens, which means they require one pull of the trigger for every round fired.
Likewise, we do not carry any 'assault weapons', since that is a vague and incorrect term that only encompasses items that have been used to assault a person, and none of these firearms has been used by an evil doer to assault anyone.
Now, what else may I help you with?"