Arcturus M4 MOD1 Variable-Cap Magazine 30/130 Rounds, Black

The Arcturus M4 MOD1 is a variable-cap polymer magazine for M4/M16 AEGs in black that can be run as a 30-round real-cap or a 130-round mid-cap. The magazine has a modern, ergonomic design with textured grip surfaces and a window in the side, so you can see how far down the magazine you are.

The M4 is the most widely used AEG platform on airsoft sites, so the choice of magazine is often what sets one loadout apart from another. Variable-cap magazines like the MOD1 let you run the same magazines at real-cap events and on regular skirmish days. You don't need to invest in two sets of magazines, and your vest looks the same whichever capacity the site requires.

Arcturus M4 MOD1 – key features

Key features and why they matter:

• 30 or 130 rounds: Real-cap for milsim and capacity-limited games, mid-cap for regular games – without the winding and rattle of a hi-cap magazine.
• Side window: A glance at the window shows whether the magazine is nearly empty, so you can change at a quiet moment rather than in the middle of a firefight.
• Removable base plate: The base plate can be removed, and the capacity insert sits underneath – the supplier's images show the construction.
• Ergonomic polymer shell: Textured grip surfaces give a better hold with gloves, and polymer is light and can take being dropped during quick magazine changes.
• Black colour: The colour makes it easy to match the magazines to the replica's finish and the rest of your loadout.

Maintenance and safety

• Use clean, Seamless BBs – deformed or dirty BBs are the most common cause of feeding problems in mid-cap magazines.
• Empty the magazine after the game so the spring is not under tension for long periods.
• Keep the window and feed lip free of dirt and sand, and wipe the magazine after games in wet weather.
• Always wear approved eye protection when the replica is loaded.