International Legal Affairs


Following the tragedy in Las Vegas, there has been an outcry in the firearms industry as to the legality of a “bump stock” and the legality of an accessory of that nature. To those outside of the U.S., the review process and applicability of firearms law must seem arbitrary and utterly confusing. Nevertheless, if one understands the interaction of history, law and regulation, it’s quite easy to understand the issue of bump stocks and other rules in the U.S.

To understand the bump stock, one needs to go back to the Firearm Owners Protection Act (FOPA) of 1986. Prior to 1986, civilian-legal machine guns could be manufactured and sold, subject to a $200 transfer tax. The FOPA changed that. The bill was passed into law on May 19, 1986, and made the new manufacture of civilian-legal machine guns illegal.

In 1986, machine guns were mostly limited to a small core group of collectors and enthusiasts. Prices for a machine gun were expensive, but still within the reach of cost for most shooters. Machine Gun News and Soldier of Fortune magazines regularly discussed the civilian ownership of machine guns, but their readership and reach was limited. It wasn’t until the dawn of the Internet in the mid-’90s that Internet forums became widely available, and that the exchange of information became much easier. As the AR-15 rifle and other “modern sporting rifles” became more accepted and commonplace, it was only a matter of time before machine guns also became more sought after. As interest in civilian-legal machine guns increased, the prices also increased—guns manufactured prior to May 19, 1986, were still legal. Increased demand, combined with a fixed supply, will result in increased prices.

The price of pre-1986 machine guns continued to rise through the 1990s to the present. In the mid-2000s, the price of machine guns started to exceed the reach of most consumers. It wasn’t uncommon for a converted AR-15 to exceed $10,000. A true Colt M16 was much more. When the majority of shooters could no longer afford civilian-legal machine guns, innovation came along to work within the existing law and regulation.

In the mid-2000s, the first bump fire stock was introduced. Christened the “Akins Accelerator,” the original version used a spring to simulate fully automatic fire. A sample on an SKS was sent to the Firearms Technology Branch of ATF, and the design initially received legal approval. Production of the Akins stock was initiated for a different rifle, and sales started to rocket. Within months, ATF was asked to re-examine their opinion on the legality of the Akins design. The Akins design used a spring within the stock to simulate fully automatic fire; ATF determined that the spring converted the prior existing semiautomatic rifle into a fully automatic rifle, and was now illegal. Removal of the spring made the system legal, but the stock no longer functioned as intended. The solution: create a bump fire stock that did not use a spring.

The FOPA of 1986 was very specific in how it classified a “machine gun.” The law states that a machine gun is “any weapon which shoots, is designed to shoot, or can be readily restored to shoot, automatically more than one shot, without manual reloading, by a single function of the trigger.” The determination of whether a firearm is a machine gun is defined by the function of the trigger. The trigger for an M4 rifle mechanically functions differently than that of a semiautomatic AR-15 trigger. This is a cut-and-dry example of trigger function and legality. A larger issue arises when the trigger of an AR-15 rifle functions the same when utilized with a standard stock, or when placed within a bump fire stock. There is no functional difference, and by law, the bump fire stock is legal.

As the cries for additional laws and regulation rise in volume, one must remember that ATF does not write or create law—only the U.S. Congress can write laws. Laws are drafted and approved by Congress, and sent to the president for approval. When signed by the president, the proposed bill becomes law. This is where ATF (and most other federal agencies) comes into play. Congress has no ability to monitor or enforce laws; federal agencies are tasked with this job. As a result, ATF is tasked with implementing and writing rules and regulations based upon the laws passed by Congress. The rules and regulations written by the federal agency are not subject to review. Instead, most new rules and regulations are required to go through a notice-and-comment process, where industry and citizens may comment on the process, and propose alternate means of enforcing the law.

The enacted rules and regulations may not exceed the scope of the law. If one believes that the rules and regulations exceed the scope of the law, the courts are asked to step in to make a determination. Regulations that exceed the scope of the law are deemed null, and are not enforceable.

Apply existing law and regulation to the bump fire stock, and one can understand how and why the device is legal. Rick Vasquez, the (then) assistant branch chief of the Firearms Technology Branch at ATF was tasked with examining the device in 2010. The invention of the bump fire stock did not alter a gun’s trigger mechanism, as defined by the law. There were no springs, hydraulics or electric current involved. At a minimum, the stock only made the existing semiautomatic rifle fire faster. As a result, it did not violate the law that bans the manufacturing of machine guns. More importantly, the devices were being sold for as little as $100. Where a civilian-legal machine gun now cost thousands of dollars, the bump fire stock could legally replicate the same effect at a reasonable cost.

Of course, the answer is not to impose additional laws and regulations. The bump fire stock is legal in the U.S., will continue to be legal until Congress passes a new law. The bump fire stock was invented as a result of existing law and economics. Without the passage of the FOPA in 1986, the bump fire stock would never have been invented.

Mr. Wong is a Washington licensed attorney. He regularly provides legal counsel to the firearm and defense industry via his law firm, The Firearms Law Group. Mr. Wong also maintains Hurricane Butterfly, an import/export company that assists U.S. firearm manufacturers and foreign buyers wade through the regulatory morass of U.S. import/export regulations. He may be contacted via email at