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How to Build a Legal AR-15 in California

5D Tactical - 22nd Aug 2022

For firearms, California is one of the most authoritarian states in terms of regulations. Therefore, if you want to build your own AR-15 rifle, you must know which 80 lower for sale can be installed for the firearm to be legal.

Fortunately, the team at 5D Tactical can offer guidance on your next project. However, as the world changes, so too will its laws and regulations regarding firearms, so pay close attention.

Legal Disclaimer: 5D Tactical remains a loyal and staunch supporter of the Second Amendment, however, we are not lawyers. The information provided in this blog is meant to be a service to the public and is not meant to be taken as legal advice.

Please stay up to date with your local and state laws regarding gun control laws. If you need a definitive answer do your own research as well, otherwise, consult your own attorney.

California AR-15 Legislation: Magazines and Bullet Buttons

The good news, and perhaps one of the few saving graces, is that California allows for detachable magazines and standard-capacity magazines. In 2017, California passed Senate Bill 880, known as the Bullet Button Ban, in which they redefined their definition of a fixed magazine.

In S.B. 880, legislators stated: “[A fixed magazine is] an ammunition feeding device contained in, or permanently attached to, a firearm in such a manner that the device cannot be removed without disassembly of the firearm action.”

Bullet buttons do not require the user to disassemble the upper and lower receivers to remove a magazine. Therefore, according to the new legislation, they are no longer fixed magazine conversions for the AR-15.

Featureless AR-15s: Parts Banned In California

A California compliant AR-15 must be “featureless.” This means that you cannot use a few, specific components to construct your rifle.

In California, a legal AR-15 cannot feature any of the following:

  • Pistol grip
  • Thumbhole stock
  • Folding/telescoping stock
  • Flash hider
  • Underbarrel grenade or flare launcher
  • Forward pistol grip

Pistol Grip

A vertical pistol grip would allow you to completely wrap your hand around the grip and use the trigger simultaneously. California banned their use.

Thumbhole Stock

While not incredibly common, a thumbhole stock, which combines the stock with the grip, allows the user to control recoil and use the trigger with ease.

Folding/Adjustable Stock

If you want a California compliant AR-15, invest in a fixed stock; adjustable, folding, and telescoping rifle stocks are banned.

Grenade or Flare Launcher

California is not alone in banning grenade or flare launcher underbarrel attachments on rifles. The 40mm grenade launcher — used by the U.S. military — is a Class III NFA item, though 37mm launchers are purchasable outside of California.

Forward Pistol Grip

A forward pistol grip or vertical grip located anywhere along the handguard is a no-go in California.

Are 80% Lowers Legal in California?

Actually, yes. California allows 80% lowers, though they do regulate their sale and usage. For instance, when you build an 80% rifle in California, you must undergo a background check before milling the blank receiver.

Furthermore, California requires all 80% firearm owners to apply for a serial number via the California Department of Justice. Once you receive your number, it must be engraved somewhere on the lower receiver.

What about AR Pistols in California?

You may like the term “short-barrel rifle,” but in California, it’s the AR pistol. Like the AR-15, the AR pistol must adhere to California’s firearm laws and regulations.

Also, you may not have a threaded barrel or handguard attached to your AR pistol. If you want a muzzle device — one approved by the state — it will need to be welded on.

Like with 80% rifle builds, 80% AR pistol builds are legal. Again, you must serialize your lower before completion, and it cannot feature any of the previously mentioned banned items that would designate your new pistol as an “assault weapon.”

Are Flash Hiders Legal in California?

No, California banned using a flash hider.

However, they did not altogether restrict muzzle brakes or compensators.

Therefore, you’re permitted to purchase and attach any component that isn’t considered a “flash hider.”

California-Safe Muzzle Devices

If the product description mentions suppressing or flash hiding, then forego your purchase. But if you want a safe muzzle device offering recoil reduction and thread protection, here are a few top choices:

  • Precision Armament M4-72 Severe Duty
  • DPMS Miculek Compensator
  • VG6 Gamma 5.56 Muzzle Break
  • Strike Industries J-Comp v2
  • SLR Synergy Linear Hybrid Compensator
  • SureFire ProComp

Are you ready to build a California compliant AR-15? An 80% rifle kit will allow you to construct a firearm ingrained with your style and with parts of your choosing — so long as they’re legal under California law.

Build a California-Legal AR-15 Rifle with 5D Tactical

To own a firearm is an American tradition with firm roots in our Bill of Rights. At 5D Tactical, we believe that our 2nd Amendment rights extend to the construction of firearms as well.

All over the country, there are thousands of DIYers who enjoy building a rifle in the comfort of their own workshops. After all, there’s nothing like the feeling of firing a rifle you’ve built for the first time.

If you want to build a carbine in California, then it’s vital that you stay current on local laws and regulations. For help building a compliant AR-15, reach out to our team today.