Three Grandfathering Dates and the Burden of Proof

I own pre-ban magazines and firearms. How do I prove they are legal, and whose job is it to prove they are not?

Three Dates, Three Categories

September 13, 1994 applies to large capacity feeding devices (magazines holding more than 10 rounds or 5 shotgun shells). Under Section 131M(c) as amended by Chapter 135^[1], pre-1994 LCFDs are now severely restricted in where they may be possessed: essentially only at home, private property, licensed ranges, and in transit, stored unloaded in a locked container.

July 20, 2016, the date of AG Healey's Enforcement Notice on Prohibited Assault Weapons, applies to copies or duplicates of enumerated banned firearms (Colt AR-15, AK variants, UZI, etc.). Chapter 135 codified this notice: a copy or duplicate is not considered such if it was "lawfully possessed in Massachusetts, registered and serialized prior to July 20, 2016" and has fewer than two prohibited features.

August 1, 2024 applies to all firearms meeting the expanded "assault-style firearm" definition under Chapter 135. Section 131M(b)^[2] provides that the ban "shall not apply to an assault-style firearm lawfully possessed within the commonwealth on August 1, 2024" by an LTC holder, provided it is registered under Section 121B and serialized under Section 121C. The phrase "within the commonwealth" bars importing pre-ban firearms from out of state after this date.

Who Bears the Burden?

Under the old Section 131M, the prohibition included the phrase "not otherwise lawfully possessed on September 13, 1994" as part of the crime's definition, arguably requiring the Commonwealth to prove the negative. Chapter 135 restructured this: Section 131M(a) now contains a flat ban, and Section 131M(b) provides a separate exception ("shall not apply to"). This "shall not apply" structure could be interpreted as an affirmative defense, shifting the burden to the defendant. The Massachusetts Superior Court Model Criminal Jury Instructions for large capacity weapon possession (Instruction 7.630, revised November 2024) do not list pre-ban status as an element the Commonwealth must prove, supporting this interpretation. No published Massachusetts appellate decision has addressed this burden question.

The Magazine Problem

The evidentiary problem is acute for magazines. Unlike the federal AWB (which explicitly placed the burden on the government and required taking unmarked magazines at face value), Massachusetts adopted no evidentiary standard. As NortheastShooters' AWB FAQ notes, "90% of the preban magazines in existence will not have any type of marking." Current-production magazines exist that are completely indistinguishable from pre-ban ones.

Some identification methods exist. Glock U-notch vs. ambi-notch cutouts, East German AK magazines (the country ceased to exist in 1990), date stamps on some models, and "Restricted - Law Enforcement/Government Use Only" stamps that definitively mark post-ban items. But these methods are inconsistent and require specialized knowledge. Glock has reportedly declined to provide expert witnesses, and no Massachusetts court has established standards for expert testimony in pre-ban identification cases.

Key Case Law

The leading case on the assault weapons ban framework is Commonwealth v. Cassidy, 479 Mass. 527 (2018), which held the Commonwealth must prove the defendant knew a feeding device was "large capacity" or could hold more than 10 rounds. The case did not address pre-ban proof because the defendant's weapons were clearly post-ban. Worman v. Healey, 922 F.3d 26 (1st Cir. 2019)^[3] upheld the AWB's constitutionality but likewise did not address the proof burden.

Serialization Trap

GOAL's analysis warns that the serialization requirements of Section 121C^[4], requiring numbers "placed in a manner not susceptible to being readily obliterated, altered or removed," may be impossible for any commercially manufactured firearm to meet. This creates a potential trap that renders all firearms technically non-compliant.

Penalties and Practical Cost

Penalties for Section 131M violations range from 1 to 10 years imprisonment. Violations of c. 269, Section 10(a), the general unlicensed carrying statute, carry mandatory minimums starting at 18 months. These are separate statutes with distinct penalty structures. A pre-ban dispute could implicate either or both depending on the charges brought. Defense costs run in the range of $10,000 to $20,000 or more. Even a successful defense leaves the accused with arrest, pretrial detention, LTC suspension, seizure of all firearms, and reputational damage. The process is the punishment.

Bottom Line

Settled: Three grandfathering dates exist (1994, 2016, 2024), each applying to different categories. Post-August 1, 2024 importation of assault-style firearms from other states is prohibited.

Unsettled: Whether pre-ban status is an affirmative defense (defendant's burden) or an element of the crime (Commonwealth's burden). No evidentiary standard exists for proving magazine manufacture date.

Do: Maintain dated receipts, photographs with timestamps, and any manufacturer correspondence for all potentially grandfathered items.

See also: Is My Rifle Legal in Massachusetts? A Compliance Guide