A Short Guide To Building A Short Barrel Rifle

One of the most appealing parts of the AR-15 is the fact that it is so easy to customize. Its modular design, bevy of accessories and parts, and the wealth of information available on the Internet makes it easy to build the rifle to meet your needs. It’s no surprise then that nearly every AR-15 owner or builder has contemplated building their own short barrel rifle at some point. These specialized rifles are praised by competition shooters, home and self defense experts, and are used extensively by special forces and police SWAT teams.

But the cool factor of these rifles is often limited by the reality of actually putting one together. Many take a look at the paperwork that’s involved and dismiss building an SBR as a flight of fancy. However, once you have an understanding of what this paperwork is, you’ll soon find that putting together your own short barrel rifle is far easier than you first realized. Thanks to online form processing, you can now submit the paperwork to build an SBR and start building faster than ever. Let’s take a look at how you can make this happen.

Note: This information is subject to change as a result of federal regulations and state and local laws. It is your responsibility to keep current on this information in order to build your SBR legally.

Put Your Wallet Down and Pick up a Pen and Paper Instead

Thanks to the proliferation of online gun sales and expanding local gun shops, many AR-15 builders are used just ordering the parts they need and picking them up the same day. While this works for carbine and rifle-length barrels, the same cannot be said for short barrel rifles. Unlike building a normal AR-15, your preparation is more important than your parts list.

Your first step in building your new short barrel rifle is to fill out Form 1 from the Bureau of Alcohol, Tobacco, Firearms, and Explosives. Don’t be deterred by the form’s 12 pages. It’s actually more direct than you might realize. Essentially, Form 1 is your application to build your new short barrel rifle and then to register it with the ATF. Once you’ve thoroughly filled out all the pages, you should make three copies of this form. Two of these copies will be mailed to the ATF, and the third will be mailed to the Chief Law Enforcement Officer in your county, or city. In fact, it’s never a bad idea to have a fourth copy to keep with your own records. At the same time you submit Form 1, you’ll also be expected to pay the $200 tax fee. This fee is applied to the tax stamp that denotes your legal eligibility to own a short barrel rifle.

Note: at this place in the process, if you’ve purchased any components or parts to build your short barrel rifle before filling out submitting and getting approval on Form 1, you are violating the Gun Control Act and could be charged with unlawfully possessing a Class 3 weapon.

Should You Files an Individual or As a Trust?

Part of the process of filling out Form 1 is making the decision as to whether you will file as a trust or as an individual. While both will have the same end result, the processes are not the same and each comes with their own advantages and disadvantages.

Filing As a Trust

A trust is a legal entity that can own assets, including your short barrel rifle. By building a trust, you’re ensuring that the legal control of the asset can be changed without the actual ownership of the weapon changing. One of the advantages of filing as a trust is that you can add and remove trustees. This means that you can let others use your short barrel rifle without you having to be present.

Filing As an Individual

Basically, filing as an individual means that you alone have the tax stamp on the weapon. This means that you are the only one who can control, maintain, and use the weapon. Others may use your SBR only while you are present.

Your Three Major Options for Building Your SBR

After you file Form 1 and have submitted the $200 tax fee, you will have to wait for a response from the ATF. This process can take anywhere from three to six months. It’s during this time that you can start to think about what features and parts you would like to add to your short barrel rifle. Typically, AR-15 builders use one of three methods for building a short barrel rifle.

Using a Parts and Receiver Kit

Thanks to the legalities behind short barrel rifles, only the lower receiver of your AR 15 is recognized as the registered part of the short barrel rifle. This means that one of the easiest ways to build your rifle is to use an unfinished, or 80%, lower. Using an incomplete lower allows you to add your own serial numbers, trust names, and other pertinent information. Just make sure that the serial numbers and other information are at least .003 inches deep and no smaller than 1/16 of an inch. When your tax stamp is cleared and Form 1 has been approved, you can finish the lower and add the relevant information to it. Make sure you include the following information on your lower receiver:

  • The name of the gun maker (the name of the trust or your name)
  • Where the firearm was manufactured
  • The caliber of firearm
  • Serial number
  • Model number

Once this information has been engraved on the receiver either by yourself or a gunsmith, you can begin assembling your short barrel rifle. At this point, you have complete liberty in which parts and accessories you add to your custom AR-15.

Using an AR-15 Pistol

The expansion of the AR-15 market has meant that a variety of models and types of rifles have been developed. Recently, AR 15 pistols have been a popular addition to many people’s gun safes. With a new line of stabilizers or braces, you can even shoot these large pistols one-handed. By building your short barrel rifle from the pistol, you have the advantage of owning a legally functional firearm during the entire build process. Once your stock stamp has arrived, you simply add the stock and have your short barrel rifle.

Using an AR-15 Rifle

Similar to building an SBR from a pistol, once you have the tax stamp and paperwork back from the ATF, you can simply remove the 16 inch barrel from your carbine or rifle and then add a shorter barrel.

Customizing Your SBR

Once you’ve assembled the major components of your short barrel rifle, you can begin the customization process. The only real difference between your SBR and your full-size AR-15 rifle is the barrel length. That means you can add all the same accessories and parts that you would do your full-size rifle.

However, you might find that with such a short barrel your rifle performs differently. This might mean that you need to add parts like a foregrip or handstop that makes it easier to manage the recoil. Additionally, you can tune your rifle’s performance through the use of specialized parts like an adjustable gas block, new recoil spring, upgraded gas tubes, and a different bolt carrier group. Finding the wrong combination of these parts can help limit the effects of the rifle’s recoil, and improve the cycling of new rounds.

Build a Better Rifle with Bootleg

At Bootleg Inc., you’ll find the AR-15 parts and accessories you need to build your custom short barrel rifle. With complete and custom AR 15 upper receivers, adjustable gas block systems, as well as charging handles, handguards, and bolt carriers, you can build a rifle that is perfectly suited to your competition arrange time needs. Browse our complete collection of parts today and order yours.