Sure, if you banned guns in general they might be harder to access for the average person. There will be a huge market for importing illegal firearms much like modern drug smuggling. Millions if not billions that would be spent on domestically produced firearms will be sent to other countries, quite possibly to terrorism sponsoring agents. Banning stuff outright is working so well. Look at the war on drugs and prohibition.

Anyways, it's not like all the guns in this country are in dealers' hands right now. There are literally generations of firearms in this country. To rid the country of ALL of them would require some sort of authoritarian police state.