Short answer: no.
Long answer: Firearms with bores greater than .50 caliber that are deemed by the ATF to have "no sporting purpose" are controlled under the 1968 GCA as "destructive devices." That's greater than, not greater than or equal to. There have been attempts in several state legislatures (and I think Congress, too), to raise the restriction and place certain .50 caliber weapons under more restrictive laws, or to ban them altogether, but AFAIK none of them have been successful yet.
Note that this is one law with the "sporting purpose" clause. For example, most shotguns other than .410s would be under the GCA, were it not for the fact the ATF has said that they have a "sporting purpose". That's why certain shotguns such as the Street Sweeper are restricted, because they've been deemed to have no sporting purpose.
Also to be pedantic, it's not a license, it's a tax. I own a full-auto Uzi, but have no special license. I did have to pay the ATF a $200 tax to have the dealer legally transfer the gun to me. Now to deal in class 3 items, an FFL has to have a license or Special Occupational Tax, which allows them to transfer class 3 items tax free from other SOTs, but that's another situation altogether.