Sig Sauer P320 9MM 30 Round Magazine Black – 8900573

The Sig Sauer P320 Round Magazine in 9mm with 30 round capacity and a black finish is a factory extended magazine for one of the most widely used modular pistols in America. It triples what a flush fit magazine holds, and it does it with genuine Sig manufacturing rather than an aftermarket approximation. For range days and pistol caliber carbine builds, capacity is everything.

Sig Sauer makes these to the same standard as the pistols themselves, which is exactly what you want in a feeding device.

Who the Sig Sauer P320 Round Magazine Is For

Extended magazines serve a few clear purposes. On the range they cut the number of reloads dramatically, which means more shooting and less time standing at the bench pressing rounds into a follower. In competition divisions that permit them, they eliminate a reload from a stage entirely.

The Sig Sauer P320 Round Magazine also feeds the growing number of pistol caliber carbines and chassis systems built around the P320 fire control unit. Those platforms are designed for extended magazines from the start, since a flush fit magazine looks and functions oddly in a carbine sized host.

Key Features

• 30 round capacity in 9mm for extended shooting between reloads
• Factory Sig Sauer manufacture rather than aftermarket production
• Black finish that matches standard duty and range configurations
• Direct fit for the P320 family of modular pistols
• Suited to pistol caliber carbines built on the P320 fire control unit
• Robust spring and follower designed for reliable feeding at full capacity

Capacity, Construction, and Function in Detail

A 30 round magazine is a longer column of ammunition than a standard magazine, and that length places real demands on the spring. Factory magazines are engineered so the spring delivers enough force to feed the final rounds reliably while not being so stiff that loading becomes a two-handed struggle.

The follower geometry matters just as much. A follower that tips or binds inside an extended body is the most common cause of malfunctions in long magazines, which is precisely why buying factory rather than saving a few dollars on an unknown brand is the right call for anything you rely on.

The black finish keeps the magazine consistent with standard duty and training gear. It hides scuffs from dropping on concrete, which extended magazines do frequently since they protrude below the grip and land first.

Practical Use, Care, and Compatibility

Number your magazines. When something malfunctions, being able to identify which magazine was in the gun is the fastest way to isolate the problem, and it takes one paint pen and thirty seconds to set up.

Clean them periodically rather than never. Disassemble the magazine, wipe the interior of the body dry, brush the follower and the spring, and reassemble without oil inside the body, since oil attracts grit that causes exactly the binding you are trying to prevent.

Do not worry excessively about leaving magazines loaded. Springs wear from cycling far more than from static compression, so a magazine kept loaded is fine, while a magazine loaded and unloaded daily will show wear sooner.

Use a magazine loader with the Sig Sauer P320 Round Magazine if your thumbs object to seating the last several rounds. Thirty rounds of 9mm is a lot of spring compression by hand, and a loader saves both your thumbs and the feed lips from clumsy pressure.

Store spares somewhere dry and dust free rather than loose in the bottom of a range bag. Grit that works its way into a magazine body is the most common cause of the sluggish follower movement that produces feeding problems later.

Note that magazine capacity is regulated in some jurisdictions, and this item ships where state and local law allows. Browse our parts and upgrades collection for pouches, loaders, and additional magazines.

Nobody has ever finished a range session wishing they had brought fewer rounds loaded and ready. Stock up while you can. Ships direct to your door, no FFL required.