Analysis of S.2095 – Assault Weapons Ban of 2017


According to the bill the necessary and sufficient conditions for a rifle/shotgun/pistol to be an assault weapon are summarized in the text and chart below.

A semiautomatic rifle/shotgun/pistol that has the capacity to accept a detachable magazine and any 1 of the the features in Figure 1.

Figure 1 Sufficient features to classify as assault weapon

Let me first deal with the logical inconsistencies:

  • Per note {1} aren’t a “forward grip” and “a second pistol grip” functionally the same thing?
  • The capacity of the detachable magazine is not specified, but the capacity of a fixed magazine is limited.  Why are shotguns limited to a 5 round fixed magazines while rifles and pistols are allowed 10 rounds?
  • Why is a semiautomatic version of an automatic pistol consider a feature and sufficient to make it an assault weapon, while the same criteria doesn’t apply to rifles or shotguns.
  • Why is a barrel shroud sufficient in the case of a rifle or a pistol but not for a shotgun?
  • Why are revolving cylindrical magazines sufficient to classify a semi-automatic, magazine fed shotguns an assault weapon but rifles and pistols are allowed to have revolving cylindrical magazines.
  • Grenade/rocket launchers are banned (Title II) by National Firearms Act as destructive devices, there is no need to include them here.

What are these features?

Pistol Grip

For illustrative purposes I will use the military select-fire (auto/burst/semi-auto) assault rifle, to illustrate the pistol grip.

Figure 2 Pistol grip with fixed stock

The purpose of the pistol grip was ergonomic, the gunner could, while holding the grip, operate the safety, fire selector, trigger and magazine release.

It is conjectured that the pistol grip aids shooters when ‘spray firing’ from the hip.  I would be interested to know if there is any research to support this, or evidence that it played any part in a mass casualty incident.  NB! shoot from the hip usually implies inaccuracy.

Forward/Second Pistol Grip


Figure 3 Forward Grip

The function of the forward grip is recoil (bounce) control and heat mitigation.

Grenade/Rocket Launcher

Figure 4 Grenade Launcher, an independent rail mounted accessory

The M203 Grenade Launcher has been the United States Military’s primary grenade launcher since the Vietnam war. This model is the newest version, that can attach to any rail system. This version is newly manufactured by Lewis Machine & Tool (LMT). It is available in either a 9″ or 12″ configuration.

It is a completely separate  gun subsystem that mounts to the a rail system, it is NFA item, and must transfer in accordance with all NFA laws and regulations.

Barrel Shroud

Figure 5 Barrel Shroud

A barrel shroud is a covering attached to the barrel of a firearm, that partially or completely encircles the barrel which prevents operators from injuring themselves on a hot barrel.

Threaded Barrel

Figure 6 Threaded Barrel, Muzzle Brake and Silencer

A threaded barrel allows the installation of either a muzzle break or a silencer.

A muzzle brake or recoil compensator is a device connected to the muzzle of a firearm that redirects propellant gases to counter recoil and unwanted rising of the barrel during rapid fire.

A silencer is a device attached to the barrel of a firearm which reduces the amount of noise and flash.


Detachable magazine outside pistol grip (Pistols only)

Figure 7 Magazine that attaches outside the pistol grip

I can only speculate that the magazine is located outside the pistol grip to reduce the complexity of the autoload function, it does not require a slide that extends past the pistol grip.

Figure 8 Pistol grip magazine autoload mechanism

Fixed Magazines

To the best of my knowledge fixed magazines come in two styles, tubular and box.  Tubular fixed magazines are common on semi-automatic shotguns such as my grandfather’s circa 1900 Browning Sweet 16.  My experience with a box magazine is limited to my Army basic training M1 Garand.  This style is also referenced as a stripper clip.

Figure 9 Browning Auto 5 (Sweet 16)

The tubular magazine is located below the barrel from the forward strap attachment to the receiver.

Figure 10 M1 Garand with clips

For more information see Magazine vs Clip – Understanding the Terminology

Revolving Cylinder (Drum) Magazines

Figure 11 Drum Magazine for shotgun (credit:

Even though S.2095 only addresses drum magazines for shotguns they are available for both rifles and pistols.

Semi Automatic version of an automatic firearm

This one is strange enough that I will quote the bill:

“36 –  (D) A semiautomatic pistol that has the capacity to accept a detachable magazine and any 1 of the following:
“(i) A threaded barrel.
“(ii) A second pistol grip.
“(iii) A barrel shroud.
“(iv) The capacity to accept a detachable magazine at some location outside of the pistol grip.
“(v) A semiautomatic version of an automatic firearm.

The closest example of this, I believe, would be the MAC-10 and the Masterpiece Arms (not manufacturer of MAC-10) MPA10T semi-automatic (top cocker) pistol.

Figure 12 Mac-10 automatic pistol
Figure 13 MPA10T semi-automatic pistol with barrel shroud extension

What are the necessary and sufficient, gun specific, condition to decrease the lethality of mass shootings?

  1. cyclic rate-of-fire, e.g. rounds per minute
    1. 900 rounds per minute (rpm) for full auto
    2. 45 rounds per minute for semi-auto rifle
  2. magazine capacity
  3. reload time
  4. muzzle velocity (a function of cartridge and barrel length)
  5. shotgun specific
    1. size of shot
    2. scatter

With the exception of magazine capacity, which is only tangentially referenced none of these are addressed in Senate-2095.  Senate-2095 does address increased cyclic rate-of-fire, via bump stops, but does not address the designed rate-of-fire.


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