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Building a California Compliant AR-15

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One of RECOIL’s staffers lives behind the iron curtain, in sunny California. You might be surprised by how many shooters live in the state, despite its aggressively freedom-hating political leadership. Years ago, he bought a SIG Sauer M400 rifle that had been neutered for California with a device called a bullet button, which would only release a 10-round magazine with the use of a tool or tip of a bullet. When California politicians passed yet another law requiring the registration of rifles equipped with bullet buttons, rather than registering it, he disassembled it to remain legal and put in the back of his safe.

But that’s not his only option — in California, you can freely own a magazine-fed semi-automatic centerfire rifle as long as it doesn’t have certain features that the state has deemed particularly offensive, such as a pistol grip, collapsible stock, and flash hider, among others. If you do this, you can retain normal functionality with your magazines and also use standard-capacity mags. This allows you to maximize its capabilities as best you can within the law; gun guys in California call this a “featureless” build (see page 78). So, we helped him put one together.

His SIG is a great rifle, but it came with several verboten features. Therefore, he reconfigured the lower to make it “featureless,” and built a brand-new upper while he was at it, so he can swap uppers for the task at hand.

Since our staffer also frequently travels to Arizona and other parts of free America, he fitted the rifle to be easily reconfigured for out-of-state use. He replaced its collapsible stock with VLTOR’s ARM fixed riflestock, a fully featured stock with a great cheek weld, storage compartments, and QD sockets. It also fits on a standard carbine receiver extension and can be swapped out by releasing its locking latch, if you wish to switch to a collapsible stock. To get rid of the pistol grip — as defined by state law — he attached a Solar Tactical Kydex grip wrap around the original grip, preventing the user from wrapping their thumb around the grip. He did this rather than install a purpose-built California-legal featureless grip because it’s easier to remove and reinstall the wrap for out-of-state trips than the entire grip. Finally, he installed a standard magazine release from Strike Industries and upgraded the trigger with a flat-faced SSTAT single-stage drop-in unit from AIM Surplus, which broke crisply at 3.75 pounds.

To build a highly capable general-purpose upper to go with the newly modified lower, he installed a Faxon Firearms nitrided 16-inch mid-length gas 5.56 barrel with gunner profile and bolt carrier group in a Juggernaut Tactical billet upper and 15-inch handguard, with M-LOK slots at 3, 6, and 9 o’clock plus short Picatinny rails at the muzzle end. He topped it off with a SAIL muzzle brake and charging handle from Strike. 

For his do-it-all build, he picked an affordable do-it-all optic, Atibal’s XP8 Mirage 1-8×24 scope with first focal place reticle. The multi-coated glass is clear, and the eye box is good at 1x and expectably tight at 8x. The reticle features a mil scale, plus equally spaced holds in a tree pattern. As a FFP scope, the measurements are valid at all magnifications, but the center of the reticle becomes small when dialed back to 1x. Heavy outer stadia point to the center, and illumination helps it stand out, though it can wash out in the sun. He mounted the Atibal in Strike’s new adjustable scope mount, which slides fore and aft to adjust eye relief to your liking.

Finally, every defensive rifle should have a light and a sling. Streamlight’s 625-lumen ProTac Rail Mount 2 came bundled with a thumb-screw mount and pressure switch that mount to Picatinny rails, providing excellent ergonomics. Blackhawk’s multipoint QD sling handled carriage duties with a quick-adjust slider, plus their sportster bipod and Pic rail adapter was easy to attach when additional support was needed.

Except for the goofy-looking Kydex grip wrap, it’s hard to distinguish the final result from a free-state rifle. Some concessions are more significant than others — for instance, you won’t have as much positive control on the grip, which you’ll particularly notice with some weapons manipulations, but you can adapt pretty readily. One-handed drills suck, though. But otherwise, you can run the gun as effectively as any other.

So while California’s unconstitutional restrictions certainly shouldn’t exist in the first place, this California-legal build is still plenty capable. 

Caliber: 5.56 NATO 
Barrel Length: 16 inches
Overall Length: 36 inches
Weight Unloaded: 9 pounds
Price as Featured: $2,050 (excluding SIG M400 lower)

california compliant ar-15

Parts List

Lower receiverSIG SauerM400Previously
Upper receiverJuggernaut TacticalAR-15 billet upper receiver
Muzzle deviceStrike IndustriesSail
Gas block and tubeFaxonGas block and
HandguardJuggernaut TacticalAR-15 free float
Bolt carrier groupFaxonNitrided 5.56
Charging handleStrike IndustriesCharging handle with extended
Magazine releaseStrike IndustriesMagazine
Fire control groupAIM SurplusSSTAT single stage AR
CA-compliant Kydex wrapSolar TacticalKydex slip-on
OpticAtbalXP8 MIRAGE 1-8X24
Scope mountStrike IndustriesAdjustable scope
SlingBlackhawkMultipoint QD sling,
LightStreamlightProTac Rail Mount
BipodBlackhawkSportster pivot/traverse bipod,
Bipod adapterBlackhawkBipod pic rail


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