How Do I Build a Legal AR-15 in a Restricted State?

Why It Matters

Possessing an improperly configured rifle in a restricted state is a felony — up to 3 to 7 years in prison depending on the state. The laws are complex, feature-based, and differ from state to state. What is legal in Connecticut may be a felony in New York. Building a compliant rifle requires understanding your specific state's assault weapon definition and which compliance solutions are legally accepted.

The Detail

State-by-state assault weapon definitions:

California:
- Banned features (with detachable magazine): pistol grip, thumbhole stock, adjustable stock, forward pistol grip, flash hider, grenade/flare launcher
- Compliance options:
1. Featureless: fin grip (Kydex fin on pistol grip), fixed stock, muzzle brake instead of flash hider
2. Fixed magazine: CompMag, AR MagLock + Kingpin (requires action separation to remove magazine)
- Magazine capacity limit: 10 rounds (enforcement complicated by legal challenges)
- Must register existing AW-feature rifles or convert before deadline

New York (SAFE Act):
- Banned features (with detachable magazine): pistol grip, thumbhole stock, folding/telescoping stock, forward pistol grip, flash suppressor, bayonet lug, grenade launcher
- Compliance options:
1. Featureless: Thordsen FRS-15 stock (non-pistol grip), fixed stock, no flash hider
2. Fixed magazine: not commonly used in NY
- Magazine capacity limit: 10 rounds (loaded with max 7 was struck down, 10 stands)
- Pre-SAFE Act registered assault weapons are grandfathered

New Jersey:
- Banned features: flash suppressor, pistol grip that protrudes conspicuously, folding/telescoping stock, bayonet lug, grenade launcher, threaded barrel
- Compliance options:
1. Pin and weld a non-flash-hiding muzzle device, Thordsen or featureless stock, remove bayonet lug
2. Fixed magazine solutions available
- Magazine capacity limit: 10 rounds
- Other-firearms (non-rifle, non-pistol over 26 inches) exist in a legal gray area

Connecticut:
- Named ban list plus feature test similar to NY
- Pre-ban registered assault weapons grandfathered
- Magazine limit: 10 rounds
- Must have certificate of possession for pre-ban rifles

Massachusetts:
- Copies the 1994 federal AWB language plus AG enforcement notices
- AG Healey's 2016 enforcement notice expanded the definition beyond the statutory text
- Fixed magazine or featureless configurations
- Magazine limit: 10 rounds (pre-ban magazines are legal)

Maryland:
- Named ban list (specific makes and models) plus copies
- AR-15 lower receivers are NOT banned — only complete rifles matching the ban list
- Heavy barrel (HBAR) AR-15s are specifically exempt
- Build an HBAR AR-15 and it is legal with standard features
- Magazine limit: 10 rounds (can possess, cannot buy/sell/transfer within the state)

Compliance products:
- Fin grips: Kydex wraps, Shark Fin, Exile Machine Hammerhead
- Fixed stocks: Thordsen FRS-15, Strike Industries, Hera CQR
- Fixed magazine: CompMag, AR MagLock + Kingpin, Mean Arms MA Lock
- Muzzle devices: muzzle brakes, compensators (not flash hiders), thread protectors with pin-and-weld

Build Impact

Before building in a restricted state: read the actual statutory text, not just blog summaries. State laws change through legislation, court rulings, and AG enforcement actions. Join your state's firearms owners association for current legal guidance. Consider consulting a firearms attorney before your build — a 30-minute consultation ($100 to $200) is cheaper than a felony defense. Document your build with photographs showing compliance features. Keep a copy of the relevant statutes with your rifle.