If we can restrict certain groups from owning guns, how about we go after:
Brown People
Jews
Gays
Women
Men under 5'5"
Men over 6'2" (what do they need a gun for anyhow? hunting!? give them a spear)
Native Americans
Redheads
Persons with non-blue eyes
People who look like their ancestors MAY have been brown.
Free masons
I'm sure we'll think of more to add to the list later....