AR15 Magazines and Their Importance

Project ar15 Sep 09, 2023
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Ar15 magazines

It's a Magazine, not a Clip. Function and Composition.

Got a spare Mag? I hope so! Magazines are ammunition feeding devices that are a critical component of the AR15. Most semiautomatic firearms utilize some kind of magazine to supply ammunition from shot to shot. Magazines are inserted into the magazine well and are held inplace by the magazine catch. Once the last round in a magazine is fired, the follower will push up the bolt catch. Locking back the bolt for faster reloading. This eliminates the need to "Charge" the AR15 after every magazine.  AR15 Magazines are relatively inexpensive and come in many colors, materials and capacities. And just like any other component of the AR15, there are a plethora of options to choose from. The shape of a magazine will vary from caliber to caliber to fit the particular shape of that cartridge. Proper and consistent feeding is VITAL to the operation of the AR15 system.

Ar15 Magazines are generally composed of 4 parts. 

The housing. This is the hollow structure that provides a place for the ammunition. Generally they are polymer, aluminum or steel. Most new AR15s today come standard with a 30 round Magpul PMAG.

 Ar15 magpul pmag magazine


The spring. These are generally made of steel to ensure longevity and powerful upward force to push the ammunition up to the feeding lips, where it can be stripped from the action of the bolt carrier, into the chamber.

The follower. Followers are a small "platform" that sits on top of the spring Within the magazine. Ensuring the contained ammunition is kept in the proper position as the magazine feeds.

And a baseplate. Baseplates can be removed for cleaning, maintaining and modifications. 

As previously mentioned our article, AR15 Creation and History (project-ar15.com) USGI magazines initially used by the AR15 were needing some help. Jamming was a reoccurring issue due to tilting of the follower. This would cause the ammunition to get angled within the magazine and fail to chamber. Once the problem was diagnosed the solution was very simple...Anti-Tilt tabs were added to the follower to keep cartridges straight and aligned for consistent chambering.

 Ar15 magazine follower anti-tilt follower

How Many Rounds Does an AR15 Magazine Hold?

The capacity of an AR15 magazine can vary greatly. While 30 rounds is considered standard. Other capacities available are: 10 rounds, 20 rounds, 40 rounds, 60 rounds, 80 round quad stack, and 100 round drum magazines.

Ar15 magazine 100 round drum high capacity

There are also magazine accessories including identifying bands for quick caliber identification, magazine extensions for increased capacity and magazine couplers which allow the connection of 2 magazines to ride side-by-side. While having a universal shape (within each caliber) the construction material of magazines does vary, as mentioned above. Steel magazines Are the most durable however they are also the heaviest, This is where the aluminum magazines come in. A lighter metal version. Then there is polymer. An even lighter version still. While receiving some criticism, polymer magazines have solidified their place in the AR15 world of parts. And have proven to be a RELIABLE choice.

Advancing the Ar15 Magazine

As with all other AR15 parts and components ingenuity cannot and will not stop. Manufactured by Lancer, the "Advanced Warfighter Magazine" is a polymer-steel hybrid. Where polymer is used for the body, the majority of material to keep weight low. While the upper most portion, the feed lips, are made of steel.

Ar15 polymer/steel hybrid magazine

In modern magazine usage, damaged feed lips are the number one cause of malfunctions in the AR15 platform. Despite their durability and functionality all magazines will eventually wear out or become damaged. Springs and followers can be replaced. But There is little to no substitute for damaged housing or feed lips. So our advice is to get yourself 5 or so magazines, per rifle. More is preferable. Try several brands made for the caliber of your AR15. Find the brand or type that best suits you and your AR15.