Can I buy a firearm after my marijuana percription expires?

Could you buy one before? Because you heard wrong.

The ATF has no access to the Medical Marijuana registry. That MMJ recommendation / card does not change availability of a gun and the State requirements for possessing a firearm. Look up the CA requirements for gun ownership.

Here is the text of the Mass gun permit requirements: Section 129B. A firearm identification card shall be issued and possessed subject to the following conditions and restrictions:

(1) Any person residing or having a place of business within the jurisdiction of the licensing authority or any person residing in an area of exclusive federal jurisdiction located within a city or town may submit to the licensing authority an application for a firearm identification card, or renewal of the same, which the licensing authority shall issue, unless the applicant:

(i) has ever, in a court of the commonwealth, been convicted or adjudicated a youthful offender or delinquent child, both as defined in section 52 of chapter 119, for the commission of: (a) a felony; (b) a misdemeanor punishable by imprisonment for more than two years; (c) a violent crime as defined in section 121; (d) a violation of any law regulating the use, possession, ownership, transfer, purchase, sale, lease, rental, receipt or transportation of weapons or ammunition for which a term of imprisonment may be imposed; or (e) a violation of any law regulating the use, possession or sale of controlled substances, as defined in section 1 of chapter 94C including, but not limited to, a violation under said chapter 94C; provided, however, that except for the commission of a violent crime or a crime involving the trafficking of controlled substances, if the applicant has been so convicted or adjudicated or released from confinement, probation or parole supervision for such conviction or adjudication, whichever is last occurring, not less than five years immediately preceding such application, such applicant's right or ability to possess a non-large capacity rifle or shotgun shall be deemed restored in the commonwealth with respect to such conviction or adjudication and such conviction or adjudication shall not disqualify such applicant for a firearm identification card;

(ii) has, in any other state or federal jurisdiction, been convicted or adjudicated a youthful offender or delinquent child for the commission of: (a) a felony; (b) a misdemeanor punishable by imprisonment for more than two years; (c) a violent crime as defined in section 121; (d) a violation of any law regulating the use, possession, ownership, transfer, purchase, sale, lease, rental, receipt or transportation of weapons or ammunition for which a term of imprisonment may be imposed; or (e) a violation of any law regulating the use, possession or sale of controlled substances, as defined in section 1 of chapter 94C; provided, however, that, except for the commission of a violent crime or a crime involving the trafficking of weapons or controlled substances, if the applicant has been so convicted or adjudicated or released from confinement, probation or parole supervision for such conviction or adjudication, whichever is last occurring, not less than five years immediately preceding such application, and such applicant's right or ability to possess a rifle or shotgun has been fully restored in the jurisdiction wherein the subject conviction or adjudication was entered, such conviction or adjudication shall not disqualify such applicant for a firearm identification card;

(iii) has been confined to any hospital or institution for mental illness, unless the applicant submits with his application an affidavit of a registered physician attesting that such physician is familiar with the applicant's mental illness and that in such physician's opinion the applicant is not disabled by such an illness in a manner that should prevent the applicant from possessing a firearm, rifle or shotgun;