U.S. Department of Justice
Bureau of Alcohol, Tobacco,
Firearms and Explosives
Assistant Director
Washington, DC 20226
www.atf.gov

APR 16 2013

The Honorable Ed Perlmutter
U.S. House of Representatives
Washington, DC 20515
Dear Congressman Perlmutter:
This is in response to your letter dated March 5, 2013, to the Bureau of Alcohol, Tobacco,
Firearms and Explosives (ATF) to rescind a previous evaluation letter and to classify all bumpfire stocks (to include specifically the Slide Fire Solutions stock) as machineguns.
As you have indicated, machineguns are defined in the National Firearms Title Act, 26 United
States Code Chapter 53 Section 5845(b). The definition has four distinct parts. The first, as you
point out, states that a machinegun 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 remaining portions of the definition go on to state that: "[t]he
term shall also include the frame or receiver of any such weapon, any part designed and intended
solely and exclusively, or combination of parts designed and intended, for use in converting a
weapon into a machine gun, and any combination of parts from which a machine gun can be
assembled if such parts are in the possession or under the control of a person."
In the course of examining a number of bump-fire stocks, ATF found that none of these devices
could shoot nor did they constitute firearm frames or receivers; therefore, the first portion of the
machinegun definition can not apply. Those bump-fire stocks which were found to convert a
weapon to shoot automatically were classified as machineguns and regulated accordinglymost notably, the Akins Accelerator. Other bump-fire stocks (such as the SlideFire Solutions
stock) that ATF determined to be unable to convert a weapon to shoot automatically were not
classified as machineguns.
Reviewing findings with respect to the Akins and Slide Solutions, ATF, in Ruling 2006-2, found
that the Akins Accelerator incorporated a mechanism to automatically reset and activate the firecontrol components of a firearm following the single input of a user. Thus, the Akins
Accelerator acted to convert a semiautomatic firearm to shoot automatically. Conversely, the
Slide Fire Solutions stock requires continuous multiple inputs by the user for each successive

 -2-

The Honorable Ed Perlmutter

shot. Similarly, other devices exist, such as the HellFire Trigger, which attach to and act upon
the trigger of a firearm and also work to increase the rate or volume of fire of the firearm. Like
the Slide Fire Solutions stock, the HellFire Trigger does not provide an automatic actionrequiring instead continuous multiple inputs by the user for each successive shot.
Public safety is always a primary concern of ATF. We remain committed to the security of our
Nation and the fight against violent crime. However, bump-fire stocks that do not fall within any
of the classifications for firearm contained in Federal law may only be classified as firearms
components. Stocks of this type are not subject to the provisions of Federal firearms statutes.
Therefore, ATF does not have the authority to restrict their lawful possession, use, or transfer.
We hope this information proves helpful in responding to your constituent. Please let me know
if we may be of further assistance.
Sincerely yours,

Richard W. Marianas
Assistant Director
Public and Governmental Affairs