A California compliant Ruger 5.7 is legal to own, but you can’t walk into a gun store and buy one. The pistol isn’t on California’s handgun roster, so licensed dealers can’t sell it new. Your route is a private party transfer or an intrafamilial transfer, and the specific gun you take possession of has to have a non-threaded barrel and magazines that hold no more than 10 rounds.
Why Dealers Can’t Sell You One
California prohibits licensed dealers from selling any handgun the Department of Justice hasn’t certified and placed on its roster. Every handgun manufactured in or imported into the state for commercial sale since January 1, 2001 must first pass firing, safety, and drop tests.1State of California – Department of Justice – Office of the Attorney General. Handguns Certified for Sale The Ruger 5.7 has never been on the roster.
The roster is also functionally closed to new modern handguns. Under Penal Code Section 31910, any centerfire semiautomatic pistol newly submitted for approval must include a chamber load indicator, a magazine disconnect, and microstamping capability.2California Legislative Information. California Penal Code PEN 31910 – Unsafe Handgun No manufacturer has cleared microstamping, so the roster only shrinks. Assume the Ruger 5.7 will not be added.
The Threaded Barrel Turns It Into a Felony
Ruger produces the 5.7 in more than one configuration, and some ship with a threaded barrel for muzzle devices. Under Penal Code Section 30515, a semiautomatic pistol that accepts a detachable magazine and has a threaded barrel capable of accepting a flash suppressor, forward handgrip, or silencer meets California’s definition of an assault weapon.3California Legislative Information. California Penal Code 30515 – Assault Weapons The Ruger 5.7 uses detachable magazines, so a threaded barrel is enough on its own.
Possessing an unregistered assault weapon carries 16 months, two years, or three years in state prison. The California Attorney General lists the threaded barrel as the first prohibited pistol feature under Section 30515.4State of California – Department of Justice – Office of the Attorney General. Assault Weapons Laws (California and Federal Law) Before taking possession of any Ruger 5.7 in the state, look at the muzzle. It should be smooth and flush, with no threads, no thread protector, no knurling. If the barrel is threaded, that pistol cannot legally enter California in its current form. Check the SKU too, since Ruger makes both threaded and non-threaded versions.
Magazines Have To Be 10 Rounds or Fewer
The Ruger 5.7 ships from the factory with 20-round magazines built around the slim 5.7x28mm cartridge. California Penal Code Section 32310 prohibits manufacturing, importing, selling, or lending any magazine that holds more than 10 rounds, and possession can be charged as an infraction or a misdemeanor.
Compliant magazines are either factory-built at 10 rounds or permanently modified so they cannot accept more. A removable pin or spacer does not qualify. The modification must be irreversible. Aftermarket California-compliant 10-round magazines exist for the 5.7; verify the magazine yourself rather than relying on a seller’s “California compliant” label.
How To Legally Acquire One
Private Party Transfer
The main legal route is a private party transfer between two California residents. Penal Code Section 32110(a) exempts private-party firearm sales from the roster requirement, which is what makes off-roster handguns like the Ruger 5.7 available this way.5California Legislative Information. California Penal Code PEN 32110 The transfer still has to go through a licensed dealer. The dealer runs the background check, processes the Dealer’s Record of Sale, collects the $31.19 DROS fee, and applies the 10-day waiting period before you can pick up the gun.6New York Codes, Rules and Regulations. California Code of Regulations 4001 – DROS Fees The dealer also charges a separate processing fee that varies by shop.
Both parties bring valid California ID. The firearm has to be compliant at the time of transfer, meaning a non-threaded barrel and 10-round magazines. A dealer legally cannot process the transfer if the gun has prohibited features. You also need a Firearm Safety Certificate, earned by passing a written test at any licensed dealer.
Intrafamilial Transfer
Parent-to-child and grandparent-to-grandchild transfers (and the reverse direction) are also allowed for off-roster handguns. The recipient files paperwork with the Department of Justice, and every configuration rule still applies: no threaded barrel, no oversized magazines. This route only helps if a qualifying relative already owns a compliant Ruger 5.7 in California.
Feeding a 5.7 in California
The 5.7x28mm cartridge is uncommon, and California retailers who stock it are fewer and pricier than those carrying 9mm or .45 ACP.
Some 5.7x28mm loadings are federally restricted. Under 18 U.S.C. ยง 921(a)(17), armor-piercing ammunition includes handgun projectiles constructed entirely from steel, tungsten alloys, brass, bronze, iron, beryllium copper, or depleted uranium.7Legal Information Institute. 18 USC 921(a)(17) – Armor Piercing Ammunition The FN SS190 military load uses a steel-core penetrator and is restricted for civilian sale. The commercial FN SS197SR (polymer-tipped, lead core) and SS195LF (lead-free training) were designed to fall outside the armor-piercing definition and are legal for civilian purchase.
California runs a background check on ammunition purchases at the point of sale. If you already have a firearm in the state’s system, the standard check costs a few dollars. Without that record, expect a more involved and more expensive eligibility check. Ammunition bought online from out-of-state must ship to a licensed California ammunition vendor, who runs the check before releasing it to you.
The Compliance Checklist
A Ruger 5.7 that satisfies California law has three non-negotiable features: a barrel with no threading of any kind, magazines that hold 10 rounds or fewer (permanently modified if they started higher), and no other feature listed under Section 30515, such as a second handgrip, barrel shroud, or magazine well outside the pistol grip.3California Legislative Information. California Penal Code 30515 – Assault Weapons
On the acquisition side: a private party or intrafamilial transfer, a $31.19 DROS fee plus the dealer’s processing charge, a background check, the 10-day waiting period, and a valid Firearm Safety Certificate.6New York Codes, Rules and Regulations. California Code of Regulations 4001 – DROS Fees Skip any one of these and the possession itself becomes the crime.