Pointing to a ruling in a California case, lawyers for the National Rifle Association this week urged a federal appellate court to strike down a Florida law prohibiting sales of rifles and other long guns to adults under age 21. A three-judge panel of the Atlanta-based 11th U.S. Circuit Court of Appeals in March heard arguments in the Florida lawsuit, which the NRA filed after the Legislature passed the law in 2018 in response to the mass shooting at Marjory Stoneman Douglas High School in Parkland...