Magazines

OEM vs. Aftermarket Magazines: What to Know

Factory OEM (original equipment manufacturer) magazines are made to the same specifications as the magazine that ships with your firearm and are generally the most reliable choice for a defensive gun. For Glock, SIG Sauer, Beretta, and most major manufacturers, factory magazines are widely available and worth the slight price premium for a gun you depend on. Aftermarket magazines from reputable manufacturers like Magpul (for AR-15 and certain pistols), Mec-Gar (for CZ, Beretta, SIG, and others), and ETS (for Glock) offer reliable performance often at lower cost. For range training and competition where absolute reliability under pressure is less critical than cost, quality aftermarket magazines are a practical choice.

AR-15 Magazines: PMAG and Alternatives

The Magpul PMAG is the standard against which all AR-15 magazines are measured—it has become arguably the most widely used AR magazine in both military and civilian use for its reliability, durability, and consistent performance across all AR-15 variants. The PMAG Gen M3 in 30-round and 10-round (for restricted states) configurations is the practical first choice for most AR-15 owners. For competition, the 40-round PMAG or Lancer AWM extend capacity for stages with higher round counts. See also: AR-15 Rifles.

Glock Magazines: OEM and Compatible

Glock OEM magazines are the gold standard for Glock pistol reliability and are available in standard and extended configurations for every Glock model. The Glock 17 17-round and Glock 19 15-round are the most commonly purchased for defensive use. For competition and range use, the Glock 33-round extended magazine provides maximum capacity in USPSA and PCC competition. ETS and Magpul GL9 magazines offer reliable Glock-compatible performance at lower cost for high-volume training. Note that many aftermarket PCCs (Ruger PC Carbine, S&W Response, CMMG) use Glock-pattern magazines, making Glock mags doubly practical for owners of those platforms.

AK-47 Magazines

AK-47 platform magazines are available in steel, polymer, and mixed-construction configurations. Bulgarian Circle 10 magazines and PMAG AK/AKM magazines are widely regarded as the most reliable aftermarket options for 7.62x39 AK platforms. For 5.45x39 AK-74 pattern rifles, surplus Eastern European steel magazines are typically the most reliable choice. Magazine fit varies between AK manufacturers—verify compatibility with your specific rifle before purchasing. See also: AK-47 Rifles.

State Capacity Restrictions

Several U.S. states restrict magazine capacity, typically to 10 rounds. California, Colorado, Connecticut, Hawaii, Maryland, Massachusetts, New Jersey, New York, and Washington have magazine capacity restrictions in effect as of 2026. Impact Guns ships only compliant magazines to restricted states. If you are ordering from a restricted state, confirm the magazine capacity is compliant with your state’s current law before ordering. Our staff can assist with identifying compliant options for your platform. See also: State Legal Guns.

Frequently Asked Questions: Gun Magazines

Are high-capacity magazines legal?
At the federal level, there are no magazine capacity restrictions — standard-capacity magazines of any size are legal for civilian purchase in most states. However, California, New York, New Jersey, Connecticut, Maryland, Massachusetts, Hawaii, Colorado, Illinois, Vermont, and Washington state all restrict magazine capacity, typically to 10 rounds. Always verify your state’s current magazine laws before purchasing. Impact Guns ships magazines in compliance with all applicable state laws and will advise you if a specific magazine cannot ship to your state.

What magazines does my gun use?
Magazine compatibility is firearm-specific. Glock magazines are some of the most widely compatible — Glock 17/19/26 all use the same 9mm magazine family with different capacities. Sig P320 uses Sig-specific magazines. M&P uses S&W-specific magazines. AR-15 uses standard STANAG/AR magazines that are broadly compatible across manufacturers. When in doubt, verify the OEM magazine for your specific model before purchasing aftermarket options — using an incompatible magazine is a leading cause of semi-automatic malfunctions.

Are aftermarket magazines reliable?
Quality aftermarket magazines from Magpul (PMAG), Mec-Gar, and ProMag are reliable for most firearms. Magpul PMAGs are the standard replacement magazine for AR-15s and are more reliable than many factory magazines. Mec-Gar produces OEM magazines for Beretta, Sig, CZ, and other manufacturers — their aftermarket offerings are often equivalent or superior to factory magazines. Avoid no-name budget magazines for defensive use; feed lip consistency directly affects reliability.

How should I store magazines?
Quality modern magazines can be stored fully loaded without spring fatigue — the spring’s enemy is repeated compression and decompression cycles, not sustained compression. Storing a magazine loaded for months or years does not meaningfully weaken the spring. Rotate loaded magazines periodically to distribute wear. Keep magazines clean and free of debris; a dirty or corroded magazine is the leading cause of feeding malfunctions.

See Also: Handgun Magazines • Rifle Magazines • Drum Magazines • AR-15 Parts • Handgun Parts