3. Can I leave my gun in my car if I need to go into the store on my way home from the range or from hunting?
A: If your handgun or large capacity rifle or shotgun is transported in accordance with the provisions of M.G.L. c. 140, §131C (i.e. unloaded and in a locked case, locked trunk or other secure container) then the gun may be left unattended in the vehicle. Weapons transported in this manner will automatically be considered "stored or kept" in compliance with the safe storage requirements of §131L.
A person leaving a non-large capacity rifle or shotgun in an unattended vehicle is required to lock the rifle or shotgun in a case/container or in the trunk, or install a mechanical locking device on the weapon (i.e. cable or trigger lock).
This is from the AG's web site. I didn't think this was allowed.
Is it legal to leave a gun in your car during the day while you're at work?
Matt