NH is free by default for recreational firearms use and mere possession. Just make sure the guns are unloaded when transporting in your vehicle.
You can also open carry a handgun in NH without a permit- but beware- this provision is relatively worthless without an NH permit, because the moment you step into a motor vehicle while carrying a loaded gun you're breaking the law unless you have this permit. The permit will also allow you to legally conceal a handgun, which helps keep sheeple from whining as much.
I'd apply NOW for an NH nonres so maybe you'll get it by Christmas or so.
You can legally buy firearms in NH, but beware that if you buy a handgun, it will have to pass through an MA FFL before you can actually take possession. Also beware that the handgun must be compliant..... so take that into consideration as well.... otherwise the MA FFL might bounce the transfer and you'll be out a lot of money. (Chances are you'll lose any fees, etc, and the NH dealer might hit you with a restock fee or some crap... although many NH dealers won't even send any handguns into MA FFLs because of
the potential for this kind of problem. )
Also beware that the MA AWB still applies on rifles and shotguns, and large capacity mags you bring back into MA. Most gun stores in free states do not know the laws very well here- so it's possible for you to buy something that isn't legal here, and possibly be breaking a law when you come back over the line.
Know the laws before you buy. DO NOT ever depend on any gun store or FFL for legal advice.
If you buy rifles/shotguns in NH, ME, or wherever, you will also need to remember to file an FA-10 within 7 days when you bring it back into the state.
-Mike