Specifically for handguns:
- if you're a felon, you cannot have a handgun in your possession. Period.
- if you don't have a valid Maine concealed firearm permit (or one honored by Maine), the gun must be unloaded and the ammo separated from the gun (remove the magazine) while in your vehicle.
- exception is if you feel your life (or the lives of those in your vehicle) is being threatened, then you can have a loaded weapon and discharge the same in the direction of the threat.
- an exception for rifles, all rifles must be unloaded while in your vehicle, permit or no permit
- however, Maine is an open carry state, so while not in your vehicle, you can carry openly without a permit (no carry whatsoever in school zones, US post offices, etc.)
- if you do have a valid Maine concealed firearm permit, you can transport a loaded handgun, or 2 or 3 or whatever.
- Maine is a "preemptive State" which means no municipalities can enact ordinances that negate State law...meaning Maine gun laws are what the State says they are, not the individual municipalities.
- Exception to "State preemption", each municipality can determine, for non-life threatening situations, where you can discharge firearms (within city limits, outside city limit, etc). This exception does not pertain to carrying (concealed or openly), only to discharge during non-life threatening yadda yadda you get the idea.
- Maine has a "Castle Doctrine" but not "Stand Your Ground"; however the "duty to retreat" doesn't override "imminent danger", if you "feel" that your life is in imminent danger, you don't have a duty to retreat; otherwise, you need to retreat. Like I said, not cut-and-dry
- If you witness someone about to commit arson (and only for arson/attempted arson), you are at liberty to stop them using whatever means are at your disposal
Shooting on your property:
- this is determined by a bunch of things: what types of property abuts to yours, school zone extended into your property, houses close too close together, road ways on the far end of the property, location of property (within city limits, outside city limits, etc)
- so maybe yes, and maybe no
- generally speaking, large tracts of land designated as farm land should be ok to target practice on since they're normally outside city limits with no schools close by, and neighbors are a fair ways down the road...but check first so that you don't get into trouble with the local constabulary.