The laws governing the legal use, storage and carrying of firearms are constantly changing. Below are the applicable laws in the State of  as of 4/10/2013. The below information is designed to be a guide and not the final word. If you have specific questions, please refer to the State of New Hampshire  legislation at gencourt.state.nh.us. Another great resource is the New Hampshire Department of Public Safety.

159:1 Definition.
Pistol or revolver, as used herein, means any firearm with barrel less than 16 inches in length. It does not include antique pistols, gun canes, or revolvers. An antique pistol, gun cane, or revolver, for the purposes of this chapter, means any pistol, gun cane, or revolver utilizing an early type of ignition, including, but not limited to, flintlocks, wheel locks, matchlocks, percussions and pin-fire, but no pistol, gun cane, or revolver which utilizes readily available center fire or rim-fire cartridges which are in common, current use shall be deemed to be an antique pistol, gun cane, or revolver. Nothing in this section shall prevent antique pistols, gun canes, or revolvers from being owned or transferred by museums, antique or arms collectors, or licensed gun dealers at auctions, gun shows, or private premises provided such ownership or transfer does not conflict with federal statutes.

159:3 Convicted Felons
I. A person is guilty of a class B felony if he:
(a) Owns or has in his possession or under his control, a pistol, revolver, or other firearm, or slungshot, metallic knuckles, billies, stiletto, switchblade knife, sword cane, pistol cane, blackjack, dagger, dirk-knife, or other deadly weapon as defined in RSA 625:11, V; and
(b) Has been convicted in either a state or federal court in this or any other state, the District of Columbia, the Commonwealth of Puerto Rico, or any territory or possession of the United States of:
(1) A felony against the person or property of another; or
(2) A felony under RSA 318-B; or
(3) A felony violation of the laws of any other state, the District of Columbia, the United States, the Commonwealth of Puerto Rico or any territory or possession of the United States relating to controlled drugs as defined in RSA 318-B.
I-a. A person is guilty of a class B felony if such person completes and signs an application for purchase of a firearm and the person is a convicted felon under the provisions of paragraph I.

II. The state shall confiscate to the use of the state the weapon or weapons of persons convicted under this section.

III. It is an affirmative defense to a charge under this section that a felony of which a defendant has been convicted in another jurisdiction would not have constituted a felony in the state of New Hampshire at the time such felony was committed.

159:3 a. Armed Career Criminals.
I. No person who has been convicted of any combination of 3 or more felonies in this state or any other state under homicide, assault, sexual assault, arson, burglary, robbery, extortion, child pornography, or controlled drug laws, shall own or have in his possession or under his control, a pistol, revolver, rifle, shotgun, or any other firearm.

II. Any person who violates paragraph I shall be guilty of a felony and, notwithstanding RSA 651:2, II, shall be sentenced to a minimum mandatory term of 10 years imprisonment and a maximum term of imprisonment of not more than 40 years and shall be fined not more than $25,000.

III. Notwithstanding any other provision of law, neither the whole, nor any part of the minimum mandatory sentence provided under paragraph II shall be served concurrently with any other term, nor shall the whole or any part of such additional term of imprisonment be suspended or deferred. No action brought to enforce sentencing under this section shall be continued for sentencing, nor shall the provisions of RSA 651:20 relative to suspensions or RSA 651-A relative to parole apply to any sentence of imprisonment imposed.

TRANSPORTING FIREARMS
159:4 Carrying Without License.
No person shall carry a loaded pistol or revolver in any vehicle or concealed upon his person, except in his dwelling, house or place of business, without a valid license therefor as hereinafter provided. A loaded pistol or revolver shall include any pistol or revolver with a magazine, cylinder, chamber or clip in which there are loaded cartridges. Whoever violates the provisions of this section shall, for the first such offense, be guilty of a misdemeanor. For the second and for each subsequent violation of the provisions of this section, such person shall be guilty of a class B felony, provided such second or subsequent violation has occurred within 7 years of the previous conviction.

159:5 Exceptions.
The provisions of RSA 159:3 and 4 shall not apply to marshals, sheriffs, policemen or other duly appointed peace and other law enforcement officers, or bailiffs and court officers responsible for court security; nor to the regular and ordinary transportation of pistols or revolvers as merchandise, nor to members of the armed services of the United States when on duty; nor to the national guard when on duty; nor to organizations by law authorized to purchase or receive such weapons; nor to duly authorized military or civil organizations when parading, or the members thereof when at, or going to or from, their customary places of assembly.
159:5 a. Exceptions and Exemptions Not Required to be Negated. – In any complaint, information, or indictment, and in any action or proceeding brought for the enforcement of any provision of this chapter, it shall not be necessary to negate any exception, excuse, proviso, or exemption contained herein, and the burden of proof of any such exception, excuse, proviso or exemption shall be upon the defendant.

RESIDENT/NON-RESIDENT
159:6 License to Carry.
I.(a) The selectmen of a town, the mayor or chief of police of a city or a full-time police officer designated by them respectively, the county sheriff for a resident of an unincorporated place, or the county sheriff if designated by the selectmen of a town that has no police chief, upon application of any resident of such town, city, or unincorporated place, or the director of state police, or some person designated by such director, upon application of a nonresident, shall issue a license to such applicant authorizing the applicant to carry a loaded pistol or revolver in this state for not less than 4 years from the date of issue, if it appears that the applicant has good reason to fear injury to the applicant's person or property or has any proper purpose, and that the applicant is a suitable person to be licensed. Hunting, target shooting, or self-defense shall be considered a proper purpose. The license shall be valid for all allowable purposes regardless of the purpose for which it was originally
issued.
  (b) The license shall be in duplicate and shall bear the name, address, description, and signature of the licensee. The original shall be delivered to the licensee and the duplicate shall be preserved by the people issuing the same for 4 years. When required, license renewal shall take place within the month of the fourth anniversary of the license holder's date of birth following the date of issuance. The license shall be issued within 14 days after application, and, if such application is denied, the reason for such denial shall be stated in writing, the original of which such writing shall be delivered to the applicant, and a copy kept in the office of the person to whom the application was made. The fee for licenses issued to residents of the state shall be $10, which fee shall be for the use of the law enforcement department of the town or city granting said licenses; the fee for licenses granted to out-of-state residents shall be $100, which fee shall be for the use of the state. The director of state police is hereby authorized and directed to prepare forms for the licenses required under this chapter and forms for the application for such licenses and to supply the same to officials of the cities and towns authorized to issue the licenses. No other forms shall be used by officials of cities and towns. The cost of the forms shall be paid out of the fees received from nonresident licenses.

II. No photograph or fingerprint shall be required or used as a basis to grant, deny, or renew a license to carry for a resident or nonresident, unless requested by the applicant.

159:6-a Confidentiality of Licenses.
Notwithstanding the provisions of RSA 91-A:4 or any other provision of law to the contrary, all papers and records, including applications, pertaining to the issuance of licenses pursuant to RSA 159:6 and all licenses issued pursuant to said section are subject to inspection only by law enforcement officials of the state or any political subdivision thereof or of the federal government while in the performance of official duties or upon written consent, for good cause shown, of the superior court in the county where said license was issued.

159:6-b Suspension or Revocation of License.
I. The issuing authority may order a license to carry a loaded pistol or revolver issued to any person pursuant to RSA 159:6 to be suspended or revoked for just cause, provided written notice of the suspension or revocation and the reason therefore is given to the licensee. A licensee whose license has been suspended or revoked shall be permitted a hearing on such suspension or revocation if a hearing is requested by the licensee to the issuing authority within 7 days of the suspension or revocation.

II. When the licensee hereunder ceases to be a resident of the community in which the license was issued he shall notify in writing the issuing authority at his new place of residence that he has a current license. Such license shall remain in effect until it expires pursuant to RSA 159:6.

159:6-c Appeal From Denial, Suspension, or Revocation.
Any person whose application for a license to carry a loaded pistol or revolver has been denied pursuant to RSA 159:6 or whose license to carry a loaded pistol or revolver has been suspended or revoked pursuant to RSA 159:6-b may within 30 days thereafter, petition the district or municipal court in the jurisdiction in which such person resides to determine whether the petitioner is entitled to a license. The court shall conduct a hearing within 14 days after receipt of the petition. During this hearing the burden shall be upon the issuing authority to demonstrate by clear and convincing proof why any denial, suspension, or revocation was justified, failing which the court shall enter an order directing the issuing authority to grant or reinstate the petitioner's license. The court shall issue its decision not later than 14 days after the hearing on whether the petitioner is entitled to a license.

RECIPROCITY
159:6-d Full Faith and Credit for Licenses From Other States; Reciprocity. – Notwithstanding the provisions of RSA 159:6, no nonresident holding a current and valid license to carry a loaded pistol or revolver in the state in which he resides or who is a peace officer in the state in which he resides, shall be required to obtain a license to carry a loaded pistol or revolver within this state if:
I. Such nonresident carries upon his person the license held from the state in which he resides; and
II. The state in which such person is a resident provides a reciprocal privilege for residents of this state.

NOTE: The State of New Hampshire honors only resident permits/licenses from the states it honors.

The State of New Hampshire honors concealed carry permits/license from the states listed below:
Alabama, Alaska, Arizona, Arkansas, Colorado, Florida, Georgia, Idaho, Indiana, Iowa, Kentucky, Louisiana, Michigan, Mississippi, Missouri, North Carolina, North Dakota, Oklahoma, Pennsylvania, Tennessee, Utah, Wyoming

The New Hampshire Resident License to Carry is honored in the states listed below:
Alabama, Alaska, Arizona, Arkansas, Colorado, Florida, Georgia, Idaho, Indiana, Iowa, Kentucky, Louisiana, Michigan, Mississippi, Missouri, New Hampshire, North Carolina, North Dakota, Oklahoma, Pennsylvania, South Dakota, Tennessee, Utah, Vermont, Wyoming

The New Hampshire Resident License to Carry is honored in the states listed below:
Alabama, Alaska, Arizona, Arkansas, Georgia, Idaho, Indiana, Iowa, Kentucky, Louisiana, Mississippi, Missouri, New Hampshire, North Carolina, North Dakota, Oklahoma, Pennsylvania, South Dakota, Tennessee, Utah, Vermont, Wyoming

159:6-e Violation.
Any person aggrieved by a violation of the licensing sections of this chapter by a licensing entity may petition the superior court of the county in which the alleged violation occurred for injunctive relief. The court shall give proceedings under this chapter priority on the court calendar. Such a petitioner may appear with or without counsel. The petition shall be deemed sufficient if it states facts constituting a violation of the licensing sections of this chapter by the licensing entity, and may be filed by the petitioner or the petitioner's counsel with the clerk of court or the justice. The clerk of court or any justice shall order service by copy of the petition on the licensing entity or a person employed by the entity. If the justice finds that time is of the essence, the justice may order notice by any reasonable means, and shall have authority to issue an order ex parte when the justice reasonably deems such an order necessary to insure compliance with the provisions of this chapter.

159:6-f Remedies.
I. If any licensing entity or employee or member of the city council or board of selectmen, in violation of the provisions of this chapter, refuses to comply with this chapter, such entity or person shall be liable for reasonable attorney's fees and costs incurred in a lawsuit under this chapter to enforce the terms of this chapter, provided that the court finds that such lawsuit was necessary in order to obtain compliance with this chapter by the licensing authority. Fees shall not be awarded unless the court finds that the entity or person knew or should have known that the conduct engaged in was a violation of this chapter or when the parties, by agreement, provide that no such fees shall be paid. In any case in which fees are awarded under this chapter, upon a finding that an employee, or other official of a licensing entity has acted in bad faith in refusing to comply with this chapter, the court may award such fees personally against such employee or other official.

II. The court may invalidate an action of a licensing entity taken in violation of the provisions of this chapter, if the circumstances justify such invalidation, and may require the licensing entity to issue a license or otherwise comply with the provisions of this chapter.

III. In addition to any other relief awarded pursuant to this chapter, the court may issue an order to enjoin future violations of this chapter.

OFF LIMITS
159:19 Courthouse Security. 
I. No person shall knowingly carry a loaded or unloaded pistol, revolver, or firearm or any other deadly weapon as defined in RSA 625:11, V, whether open or concealed or whether licensed or unlicensed, upon the person or within any of the person's possessions owned or within the person's control in a courtroom or area used by a court. Whoever violates the provisions of this paragraph shall be guilty of a class B felony.

II. Firearms may be secured at the entrance to a courthouse by courthouse security personnel.

III. For purposes of paragraph I, "area used by a court'' means:
(a) In a building dedicated exclusively to court use, the entire building exclusive of the area between the entrance and the courthouse security.
(b) In any other building which includes a court facility, courtrooms, jury assembly rooms, deliberation rooms, conference and interview rooms, the judge's chambers, other court staff facilities, holding facilities, and corridors, stairways, waiting areas, and elevators directly connecting these rooms and facilities.

IV. The provisions of this section shall not apply to marshals, sheriffs, deputy sheriffs, police or other duly appointed or elected law enforcement officers, bailiffs and court security officers, or persons with prior authorization of the court for the purpose of introducing weapons into evidence and as otherwise provided for in RSA 159:5.

V. It shall be an affirmative defense to any prosecution under paragraph I that there was no notice of the provisions of paragraph I posted in a conspicuous place at each public entrance to the court building.

NOTE: Federal laws bar the public from carrying weapons within 1,000 feet of a school and federal buildings.