Can I use a 80% to build a AR pistol? [ HOW TO info ]

[GunMan0808]

If i can, will i need those silly fin wraps and muzzle brakes like the rifle versions?

What gives?

[Quiet]

How to make from an 80%...

First issue... (making a CA legal AR style pistol)

The handgun needs to be made into a dimensionally compliant bolt-action single-shot pistol or a dimensionally compliant break-top/open single-shot pistol.

Because the firearm can never had been semi-auto prior to creation, you will most likely need to build your own upper, instead of buying an existing upper and modifying it. This is because existing uppers are typically test fired by the manufacturer as a semi-auto.

In addition to installing a 0 round mag/sled that can not be removed without disassembling the firearm's action or a 0 round mag/sled that is permanently attached to the firearm or a solid magazine, the following must be done depending on the type of upper...

If the AR style pistol normally operates via direct impingement, then:
1. Do not install a gas tube.
2. Do not install a gas block or plug the gas block.
This makes it a straight pull bolt-action single-shot.

If the AR style pistol normally operates via gas-piston, then:
1. Do not install a gas piston.
2. Do not install a gas block or plug the gas block.
This makes it a straight pull bolt-action single-shot.

If the AR style pistol normally operates via blowback, then:
1. Install a dowel in the buffer tube, which prevents the buffer from moving.
^ For rimfire blowback... install a limiter/black behind the bolt carrier group, in order to prevent it from cycling.
This makes it a break-top/open single-shot.

The upper will also need a minimum 6" barrel length and the handgun will need a minimum 10.5" overall length.


Second issue... (registration)

Starting 07-01-2018, all self-made (80%) firearm must have CA DOJ marking info in order to be CA legal.
^Exemption to this:
1. Self-made firearms that are BATFE approved Title 2 firearms or have pre-2018 CA DOJ marking info engraved on it. [11 CCR 5508(a)]
2. Self-made long guns that were made before 12-16-1968. [11 CCR 5508(b)]
3. Self-made firearms that were voluntarily registered with CA DOJ before 07-01-2018. [11 CCR 5508(c)]
4. Firearms made by a 07-FFL. [11 CCR 5508(d)]
5. Self-made firearms that are considered C&R or antique. [11 CCR 5508(e)]

The CA DOJ marking info requires submitting a Unique Serial Number Application (USNA) via CFARS (CA DOJ online reporting system).
^This process will register the firearm with CA DOJ.

After receiving the CA DOJ marking info, the applicant will have 10 days to engrave it on the firearm. [11 CCR 5518]

After the info is engraved on the firearm, proof that it was done (pictures) must be submitted to CA DOJ. [11 CCR 5521]

Markings must be to a minimum depth of .003 inch and in a print size no smaller than 1/16 inch.
Markings must use Roman letters (A, B, C, etc.) and Arabic numerals (1, 2, 3, etc).

Markings must include: [11 CCR 5520]
1) CA DOJ issued Serial Numbers [11 CCR 5520(a)]
2) The model designation of the firearm. (what you call it) [11 CCR 5520(a)(2)(B)(1)]
3) The caliber the firearm is chambered in. [11 CCR 5520(a)(2)(B)(2)]
4) The first and last name of the maker of the firearm, as reported on the application. [11 CCR 5520(a)(2)(B)(3)]
5) City & State where the firearm was made. [11 CCR 5520(a)(2)(B)(4)]

If the firearm is made from a polymer receiver, then the serial number must be engraved on 3.7 ounces of 17-4 PH stainless steel that is embedded in the polymer in such a manner that removal will destroy or signifcantly damage the receiver. [11 CCR 5519]

Starting 01-01-2019, any self-made (80%) firearm that is not registered with CA DOJ can be subject to confiscation as evidence of violating CA self-made/assembled firearm laws.

Starting 01-01-2019, the transfer of ownership (selling, gifting, etc) of self-made (80%) firearms will be illegal. [PC 29180(d)(1)]
^Only exemption is for surrendering them to law enforcement for destruction. [PC 29180(d)(2),(3),(4)]


Third issue... (conversion from exempt handgun to unsafe handgun)

After CA DOJ issues their marking info, the applicant has up to 30 days to change the configuration of the firearm. This requires updating the firearm's info via CFARS and uploading pictures of the firearm in it's new configuration. [11 CCR 5522]

During 11-2018, CA DOJ BOF has released notices prohibiting the conversion of SSE2 handguns into other configurations and doing so would be considered manufacturing an unsafe handgun.

Which means, while in CA, it needs to remain a SSE2 in order to remain CA legal.

[Quiet]

What about using a factory virgin receiver?

How the factory virgin receiver was DROS'd or registered determines how and if it can legally be utilized to make a CA legal handgun.

If the factory (07-FFL created) virgin (never used to make a functional firearm) receiver was DROS'd or registered as a "rifle, receiver"; then it can not be legally used to make a "handgun" and doing so, would result in an illegal SBR and not a "handgun".

If the factory (07-FFL created) virgin receiver was DROS'd or registered as a "pistol, receiver/frame"; then it can legally be used to only make a dimensionally compliant bolt-action single-shot pistol or dimensionally compliant break-open single-shot pistol. (see post #2, first issue)
Per CA DOJ, a handgun that is made as a a dimensionally compliant bolt-action single-shot pistol or dimensionally compliant break-open single-shot pistol, needs to remain configured as such in order to remain CA legal.

If the factory (07-FFL created) virgin receiver was DROS'd or registered as a "pistol, semi-auto" or "pistol, semi-auto, receiver/frame"; then it can be used to make a semi-auto pistol that does not violate CA assault weapons laws and CA prohibited weapons laws.