Magazines for M4/M16 SHS

An M4 / AR15 magazine should meet your criteria in parameters such as magazine capacity, loading type, material, and appearance, which often adds the finishing touch to your build — and of course, price. Based on these parameters, you’ll know which magazine you need.

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Types of magazines by capacity, use and playstyle

Push mags - Mid-cap

Push mags are definitely the most commonly used airsoft magazines, especially with AEG guns.
Inside the mag is a long channel with a spring and a follower that pushes the BBs out. This simple system is reliable in terms of feeding, nothing rattles inside the mag, so it’s quieter than winding mags. The downside is the mag’s capacity and loading. Push mags for AR15 / M4 usually hold about 120 BBs, high-capacity mid-caps up to 250 BBs.

               

Push mags are filled using a speedloader — you can’t fill them without one.

Speedloader:
A speedloader is a simple device used to fill push-type mags. Speedloaders come in different designs and capacities, but the basic function is always the same. Using a plunger/button or crank, BBs are pushed through the same opening they exit from. The mag is filled within seconds.

Push mags - Low-cap/Real-cap

Real-cap or low-cap magazines are low-capacity push mags, often with a capacity of 30–90 BBs. Because of the low BB count, they are mostly used by MilSim players who want to get as close to real ammo count as possible.
 

Winding mags - High capacity/Hi-cap 

Winding mags contain a small system made up of gears and a bunch of springs. This system must be continuously wound from the bottom of the mag using a gear wheel or pull cord — hence the term “winding mag.” Winding mags are filled through an opening at the top, which is closed after loading.
The big advantage of winding mags is their capacity — AR15 / M4 types can hold around 250–300 BBs.
The main disadvantage is the rattling noise of loose BBs moving inside the mag. Another downside is the constant need to rewind during shooting.

                    

Pozor:
Winding mags must be rewound during use, otherwise they won’t feed. On average, a single wind will feed about 40–50 BBs depending on model, brand, and mag condition...

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What is MID-CAP syndrome? 

With push mags, problems can occur if the internal spring is too strong, or if the replica’s nozzle isn’t properly tuned. BBs may push against the nozzle, which might not fully open/close the feed to the hop-up chamber, creating an air leak between the gearbox and the hop-up unit. This is known as mid-cap syndrome. The solution is typically service or mag replacement (assuming the replica is properly tuned).

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Material

The material of M4 magazines usually reflects the real-steel counterpart. Classic old-school STANAGs should be metal, while most modern types (PMAG, HEX, Daniel Defense) are polymer.
Modern polymer quality is excellent — they can take a lot of abuse and are lightweight. So don’t worry about buying a mag based on your taste. The material won’t let you down.

Plastick Magazine 

                

Metal magazine

       

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What is a PMAG?

A PMAG is a type of magazine by Magpul Industries, popular due to its lighter weight and higher durability compared to the classic STANAG mag.

         

What is a STANAG? 

STANAG is a NATO standardization agreement used in the arms industry. For magazines, it means standardizing parameters and controls across weapon platforms. STANAG, as most of the community knows it, is also a type of aluminum magazine.

         

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Compatibility of airsoft magazines and manufacturers

The general rule for proper mag function in your gun is to stick to the same brand as the replica, but...

 The M4 or AR15 platform has the big advantage of wide cross-brand compatibility. So don’t be afraid to buy a mag from a different brand than your gun — M4s aren’t nearly as picky as their Russian counterparts… Kalashnikov owners will understand.

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How do I know the issue is in the magazine and not the gun? 

To verify if the issue is in the mag and not the replica, there are a few easy checks to guide you:

 

If the gun works but doesn’t feed, try gently pushing the mag upward into the gun while shooting. If it starts feeding, the mag catch may be worn out or the mag sits too low for the hop-up chamber. Alternatively, the mag may have the catch notch positioned too low.

If the gun still doesn’t feed, try flipping the gun upside down — mag facing up — while firing.
If it starts shooting, the issue is likely with the mag’s feeding system, like a weak spring or debris in the mag’s feed path.
If this doesn’t help, consult us or your service tech.

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Which brand of magazine to choose?

For M4/M16 or AR15 magazines, you can choose from brands like Specna Arms, which offer the best price/performance ratio and can feed even in high-ROF guns. The second best-selling mags for this platform come from Delta Armory and Arcturus. SHS makes the popular Hexmags, which most replicas can also run.

If you need a high-performance mag that can handle DSG builds, we recommend PTS — although they are a bit pricier.
G&G mags are also worth mentioning — we recommend them for G&G replicas as they support the gun’s mag-empty detection system.
KWA mags are better suited for KWA replicas — from experience, they can be harder to fit into some guns from other manufacturers.

 

Our tip:

If you’ve had your replica upgraded, it’s a good idea to ask your tech which mags to use. Some mags can affect feeding, while others may influence air seal by altering the gearbox-hop-up alignment.

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Maintenance of airsoft magazines

Maintenance is easy — if your mag used to feed well and now has issues, it’s probably full of dirt from BBs or the environment. In extreme cases, you may need to replace the internal spring.
Disassemble the mag following the manual or manufacturer’s video, clean it with a cloth, and lightly lube the feed path with silicone oil (apply very lightly with a cloth — over-oiling can contaminate the hop-up rubber). Then test it again. If issues persist, we recommend replacing the spring.

Our tip:

Always empty all push-type mags after gameplay. Long-term storage of fully loaded mags significantly reduces the lifespan of the feeding spring, which is crucial for proper BB feeding.
For winding mags, it’s also recommended to unload the BBs to extend the life of the internal mechanism.