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Slide Fire Analysis

Slide Fire Analysis

Rick Vasquez

When ATF makes a classification on any device, part, or firearm, the classification is based on the definitions in the Gun Control Act (GCA) and the National Firearms Act (NFA).  Also, classifications are based on any previous Rulings or court decisions based on the GCA and the NFA.

The task of making evaluations is relegated to the Firearms Technology Branch (FTB).  As the senior Technical Expert for ATF it was my role to render an opinion or concur or disagree with opinions rendered by technicians of the FTB. In relation to the Slide Fire examination, since it was submitted as a device that would enhance the rate of fire of an AR type firearm, the predominant definition used by FTB for classification was the definition of a machinegun

The complete definition of a machinegun is as follows:

As defined in 26 United States Code, Chapter 53, section 5845(b) Machinegun. The term ‘machinegun’ means 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 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 machinegun, and any combination of parts from which a machinegun can be assembled if such parts are in the possession or under the control of a person.

The first sentence of the definition of a machinegun 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,” is the basis for the determination that a slide fire stock is not a machinegun. Additionally, it was not classified as, any part designed and intended solely and exclusively, or combination of parts designed and intended for use in converting a weapon into a machinegun, a conversion device.

Another key component in determining what should be classified as a machinegun is understanding what a single function of the trigger is.  Pulling and releasing of the trigger is two functions.  The single function is pulling the trigger straight to the rear and causing a weapon to fire.  If a shooter initially pulls and holds the trigger to the rear and a firearm continues to shoot continuously, that is a firearm shooting more than one shot with the single function of a trigger. This is critical to understanding why or why not a firearm is classified as a machinegun.

The Slide Fire does not fire automatically with a single pull/function of the trigger.  It is designed to reciprocate back and forth from the inertia of the fired cartridge.  When firing a weapon with a Slide Fire, the trigger finger sits on a shelf and the trigger is pulled into the trigger finger.  Once the rifle fires the weapon, due to the push and pull action of the stock and rifle, the rifle will reciprocate sufficiently to recock and reset the trigger. It then reciprocates forward and the freshly cocked weapon fires again when the trigger strikes the finger on its forward travel.

After lengthy analysis, ATF could not classify the slide fire as a machinegun or a machinegun conversion device, as it did not fit the definition of a machinegun as stated in the GCA and NFA.

Method of Evaluation:

An item that has been submitted for classification is logged in and assigned to a firearm enforcement officer (technician) for evaluation and classification.  A tracking number is assigned and it awaits its place in the queue.

The following are procedures for how items were evaluated when I was a member of the Firearms Technology Branch. There may have been changes to those processes so I can only speak to the processes during the timeframe that I was employed at FTB.

Firearms and firearm-related accessories are submitted to the FTB for analysis from the public and firearms industry.  The item is generally accompanied by a letter of request on how the submitter wants the item to be classified as.  There are many categories of classification.  For example:  Is it an importable firearm?  Is it a sporting firearm?  Will it shoot automatically and be classified as a machinegun?  Does a component fit the definition of an accessory or a firearm, and so forth.

Housed in the FTB are Standard Operation Procedures (SOPs) that memorialize the method of evaluation for most things that are submitted.  Once a technician begins the evaluation, he will follow these SOPs in his evaluation.  Many of the items submitted are redundant and have been seen time and time again.  These items are reviewed and approved by the supervisor and the evaluation is over.  For example, handguns for importation have a factoring criteria that must meet certain points to be imported.

Items such as the Slide Fire bump fire stock is a device that would have had additional scrutiny, especially since a device of this nature had not been previously approved. Once again, any evaluation is based on the definitions held in the GCA, NFA, previous opinions and rulings.   These laws were implemented by Congress.  Rulings and opinions were authored by council with input from the Department of Treasury and the Department of Justice.

The definition of a machinegun as stated above was used for the foundation of the classification of the Slide Fire and it did not meet the definition of a machinegun.

This opinion was sent to Chief Counsel and higher authority for review.  After much study on how the device operates, the opinion, based on definitions in the GCA and NFA, was that the Slide Fire was not a machinegun nor a firearm, and, therefore, did not require any regulatory control.


The methodology of evaluation listed above has been condensed for the reader.  ATF is tasked with making classifications of items based on the GCA and NFA.  Personal opinions are not tolerated in the classification process.  The Slide Fire bump fire stock was properly classified in accordance with the definitions codified in 1968 in the GCA and Title II of the GCA which is the NFA.


Rick Vasquez

Former Assistant Chief and Acting Chief of the Firearms Technology Branch

Firearms Consultant and Security Adviser