KABA.com has outdone itself. They've done some digging, found & posted the testimony from the president of the NRA during the debates over the National Firearms Act of 1934.
I'll give you this question & answer to whet your appetite:
"The following question was asked by Congressman CLEMENT C. DICKINSON, Missouri, of the Committee on Ways and Means:
'Mr. DICKINSON. I will ask you whether or not this bill interferes in any way with the right of a person to keep and bear arms or his right to be secure in his person against unreasonable search; in other words, do you believe this bill is unconstitutional or that it violates any constitutional provision?'
...'Mr. FREDERICK. I have not given it any study from that point of view. I will be glad to submit in writing my views on that subject, but I do think it is a subject which deserves serious thought."
Read the whole thing. & please keep in mind the NFA of '34 originally included pistols but they were excluded from the final draft of the bill as there was concern that the people may not particularly stand for it.