From Amendment V of the Constitution of the United States of America:
Of course in this day and age when the Constitution is worth less than a roll of toilet paper and is less useful anything is possible. Especially in police states like MA...
They may be able to ban the .50 and take them away but I sure don't see how they can do it without paying you for it....nor be deprived of life, liberty, or property, without due process of law; nor shall private property be taken for public use, without just compensation.
Of course in this day and age when the Constitution is worth less than a roll of toilet paper and is less useful anything is possible. Especially in police states like MA...