The National Firearms Act (NFA) was enacted in 1934 in an attempt to control weapons popular in Prohibition era gang warfare. After eighty years its implementation by the Bureau of Alcohol, Tobacco, and Firearms (ATF) has become rather strange, and its controls on items like short barrels and suppressors seem archaic.
The following infographic shows a variant of the XCR with a 10″ barrel. This is a piston-operated autoloading firearm that can chamber a variety of light rifle cartridges. Under federal law the top three configurations are considered pistols, and no special controls apply to their construction, sale, or possession. (State laws can vary widely on these matters, so those are not addressed here.)
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