In the Philippines, the regulation of firearms is governed primarily by Republic Act No. 10591, otherwise known as the "Comprehensive Firearms and Ammunition Regulation Act." This law, enacted in 2013, significantly tightened the restrictions on gun ownership and increased the penalties for violations to serve as a deterrent against gun-related crimes.

1. The Core Offense: Illegal Possession

The law distinguishes between the possession of "small arms" and "Class-A" or "Class-B" light weapons. Illegal possession occurs when an individual possesses, carries, or manufactures a firearm or ammunition without the necessary license to possess and a permit to carry outside of a residence.

Penalties for Firearms

The severity of the penalty depends on the type of firearm involved:

Small Arms: Prision mayor in its medium period (8 years and 1 day to 10 years).
Class-A Light Weapons: Prision mayor in its maximum period (10 years and 1 day to 12 years). These include self-loading pistols, rifles, and submachine guns.
Class-B Light Weapons: Reclusion temporal to reclusion perpetua (12 years and 1 day to 40 years). These are weapons designed for use by two or more persons serving as a crew (e.g., heavy machine guns, portable anti-aircraft guns).

Penalties for Ammunition

Possession of ammunition without the corresponding license for the firearm is also a criminal offense:

The penalty is prision mayor in its minimum period (6 years and 1 day to 8 years).

2. Aggravating Circumstances

The law imposes higher penalties if the illegal possession is coupled with other factors:

Possession of Three or More Firearms: If a person is found with three or more unlicensed firearms (small arms or Class-A light weapons), it is considered unlicensed manufacture or "armory" possession, punishable by reclusion perpetua (20 to 40 years).
Use of Imitation Firearms: If an imitation firearm is used in the commission of a crime, it is treated as a real firearm, and the perpetrator will be liable for the same penalties as if they carried an actual weapon.
Tampering with Serial Numbers: Any person who erases or alters the serial number of a firearm faces prision mayor.

3. The "Double Jeopardy" and Absorption Rule

Under Section 28 of R.A. 10591, if a person uses an unlicensed firearm in the commission of another crime (e.g., robbery or homicide), the use of the unlicensed firearm is treated as an aggravating circumstance.

However, if the firearm used is licensed but the person has no permit to carry it, they may be charged separately for the violation of the conditions of the license.

4. Key Prohibitions and Administrative Penalties

Aside from imprisonment, the law provides for the permanent disqualification of the offender:

Revocation of License: Any violation of the Act leads to the immediate revocation of the license and permit.
Perpetual Disqualification: Those convicted of illegal possession are permanently disqualified from applying for a firearm license in the future.
Government Employees: If the offender is a public official or a member of the law enforcement agencies, the maximum penalty is imposed, alongside administrative dismissal from service.

5. Planting of Evidence

To protect citizens from "tanim-bala" (bullet planting) or the planting of firearms by law enforcement, R.A. 10591 introduced a specific provision:

Any person found guilty of planting a firearm, ammunition, or parts thereof to incriminate another shall suffer the penalty of reclusion perpetua.

Summary Table of Penalties

Violation	Minimum Penalty	Maximum Penalty
Small Arms	8 Years and 1 Day	10 Years
Class-A Light Weapons	10 Years and 1 Day	12 Years
Class-B Light Weapons	12 Years and 1 Day	40 Years (Reclusion Perpetua)
Ammunition Only	6 Years and 1 Day	8 Years
Planting Evidence	20 Years and 1 Day	40 Years (Reclusion Perpetua)

Legal Note: Ownership of a firearm in the Philippines is a privilege, not a right. The State maintains the power to regulate, and ignorance of these stringent penal provisions is not a valid defense in court.