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High-Cap AR Mags

The Beta C-Magcan help you gain true fire superiority. Photo courtesy Beta Outdoors. Photo courtesy Beta Outdoors.

A magazine is generally a place to store ammunition. When speaking of rifles, pistols and shotguns, a magazine is for storing more cartridges ready to be fed into the gun’s chamber. Such magazines may or may not be detachable. Tubular magazines are one example of a non-detachable magazine, as seen on many shotguns and a number of rifles. More commonly, we think of detachable magazines when someone mentions magazines. Mistakenly, magazines are sometimes referred to as “clips,” but while clips charge magazines, they are not themselves magazines.

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U.S. military rifles have shown a steady increase in magazine capacity. Single-shot rifles have transitioned to rifles with 5-round magazines, to 8-round magazines, and, finally to 20-round magazines in both the M14 and M16 rifles. Until pitted against the AK-47, a rifle using 30-round magazines, the 20-round M16 magazine served well. When you begin to receive incoming rounds, you want a lot of bullets outbound to gain fire superiority. The 20-round M16 magazine was replaced by a 30-round magazine to match the 30-round AK magazines.

Higher-capacity magazines are available for the M16 and variants. Some triple the standard 30-round detachable box magazine. Most raise the capacity to around 45 rounds, a 50 percent increase.

Bigger Problems?
Some problems come with increasing the magazine capacity. One is length. Extending the magazine to hold more cartridges makes it longer. The 30-round magazine already interferes with a low prone position or shooting off the bench. A 20-round magazine can be useful for prone or bench use.

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Second, though it may not always be a drawback, is weight. More ammunition equals more weight. The 5.56mm cartridge is not the heaviest round, but the weight does mount up. If you try to carry as many higher-capacity magazines as you would with 30-round mags, it will be heavier. The added weight will absorb more recoil and stabilize the gun when fired in full-auto or burst mode.

Higher-capacity magazines may also be harder to seat in the rifle. The added spring pressure, needed to reliably lift the column of cartridges, will mean it is harder to lock the magazine in place against a closed bolt carrier. Normal recommendations are to use the higher-capacity magazine as the primary, and reload with 30-round boxes.

Special Applications
Many of these magazines are not intended for combat. They are intended to enhance competition shooting games. Like car racing, competition shooting proves the concepts that may later become the norm.

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The highest-capacity magazine currently available is the Beta Company’s C-Mag. It’s been around a while and has been used by the military. It has proven reliable and capable. It avoids the long length problem by using twin 50-round drums.

With two 50-round drums, one to each side of the central mag tube, the short length, top to bottom, allows prone or bench use and balances the weight evenly. Since pushing two columns of cartridges together creates friction, graphite lube is recommended for best results.

The Beta C-Mag has an elegance and panache unmatched by the various box magazines. When you need a lot of ammunition ready to go, the Beta C-Mag will deliver. Long-term storage loading is not a problem with the Beta, either.
Beta offers two loading tools depending on your needs. The Personal Loader loads loose cartridges and the Speed Loader uses stripper clips to load the magazine. The Personal Loader was used here and worked well.

mags-surefire-100-round
SureFire’s quad-stack magazines. Photo courtesy SureFire.

A New Take
SureFire has recently announced two magazines for military applications. They have developed 60- and 100-round quad-stack magazines. The AR receiver limits the portion of the magazine entering the gun, so the top of the SureFire magazines tapers to a double column at its upper portion. Outside the receiver, the SureFire expands to a four-column cartridge stack. This packs a large number of rounds in about half the space (vertically) of the standard two-cartridge column.

To be sure, the SureFire magazines still have extended length, but for a box magazine, it’s about as compact as you can get for the capacity.

mags-dpms-cmmg-brownells
From left to right: DPMS, CMMG, Brownells and Lancer magazines for greater capacity in a firefight. Guy Neil photos

Extended Magazines
Virgil Tripp developed the STI 2011 pistol frame using a stagger-stack magazine in a 1911-pattern gun. Tripp now offers improved 1911 magazines and, more recently, extended AR magazines in two configurations. He builds 42- and 52-round magazines by adding extensions to the standard 30-round box.

The Tripp magazines are popular with practical rifle competitors—demanding shooters who will not tolerate poor performance. The extensions are robust and able to withstand being dropped on the ground, though there is little need to drop them on the ground since reloading is eliminated or minimized.

The extension offered by Nordic Components also shows the popularity of Magpul PMAGs. Their extension expands the PMAG capacity to 48 rounds.

Thermold has a 30-round magazine that extends to hold 45 rounds. This dual nature allows the tension on the spring to beeased when there are only 30 rounds loaded, but still allows the full 45-round capacity.

CMMG offers a 42-round magazine made of steel instead of polymer or aluminum. It is built from the start as higher-capacity magazine—not adding an extension. They are just like the standard military magazines, but longer. Lancer also has a polymer 48-round magazine billed for competition.

The DPMS higher-capacity magazine takes a standard 30-round tube but has an extension welded onto it that allows for 47 rounds.

The current Brownells 30-round AR magazine was used for a baseline comparison. Brownells is a military contractor, so there’s none better for comparison. The Brownells magazines are first class and recommended if you need 20- or 30-round magazines for your AR.

mags-lancer-1
Lancer’s polymer, 48-round extended magazines are designed specifically for competition.

More With 30
You may stay with the 30-round magazines but add ammunition capacity by coupling two magazines together. There are numerous available, but I tested the Brownells coupler with their magazines. The coupler mounts two 30-round magazines side by side for a fast reload that requires little motion, other than withdrawing the empty magazine and inserting the full one.

Prezine, headed by Bill Rogers, a holster design wizard, offers a coupled magazine using the Magpul PMAGs. This is a fixed unit that comes assembled. PMAGs are popular because of their reliable performance, so coupling two of them is a logical step.

There is a wide variety of higher capacity magazines available for your AR. If you have need of more ammunition, the solution is available to fit your needs.

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