What a P365 magazine extension does

A P365 magazine extension is a metal or polymer piece that attaches to the bottom of a SIG Sauer P365 magazine to increase how many rounds it holds. The P365 ships with a 10-round magazine as standard. An extension typically adds 2 to 5 rounds, bringing capacity to 12, 13, or 15 rounds depending on which extension you buy. The extension slides onto the magazine's baseplate and is held in place by the magazine's spring and follower.

Extensions are popular because they give you more ammunition without buying a second magazine or switching to a larger pistol. They cost between $15 and $40 per extension, which is less than buying a whole new magazine. The trade-off is that your magazine becomes longer and may not fit as easily in a standard holster or pocket carry setup.

Key Takeaways

  • P365 magazine extensions add 2 to 5 rounds to your standard 10-round magazine, bringing capacity to 12, 13, or 15 rounds.
  • Extensions attach to the magazine's baseplate and are held in place by the existing spring and follower inside the magazine.
  • Common brands include Taran Tactical, SIG Sauer OEM, Hyve Technologies, and Springer Precision, each with slightly different designs and round counts.
  • An extended magazine may not fit your current holster or pocket carry method, so test the fit before relying on it for daily carry.
  • Installation takes less than a minute and requires only disassembling the magazine by removing the baseplate.

How to install an extension on your P365 magazine

Installation is straightforward and takes about one minute. First, remove the magazine from your pistol and empty it completely. Press down on the magazine's baseplate (the metal or polymer piece at the bottom) and slide it off toward the rear of the magazine. The spring and follower will still be inside the magazine tube.

Slide the extension onto the magazine tube, making sure it sits flush against the top of the follower. The extension has a hollow center that slides over the magazine's body. Once the extension is in place, slide the baseplate back on from the rear, pressing it down until it clicks or seats fully. The baseplate holds everything together. Load the magazine and test it to make sure rounds feed smoothly and the extension does not come loose.

If the extension feels loose or rounds do not feed cleanly, remove it and check that the follower is sitting flat inside the tube and that the extension is fully seated. Some extensions require a small amount of force to slide on; this is normal and means they will stay put during use.

Popular P365 extension brands and their differences

Taran Tactical makes one of the most widely used extensions, available in +2 and +5 round versions. The +5 brings capacity to 15 rounds and is made of aluminum. Taran Tactical extensions are known for tight tolerances and reliable feeding.

SIG Sauer OEM extensions are made by the pistol manufacturer and come in +2 and +3 round options. These are often considered the safest choice because they are designed specifically for the P365 by the company that made it. They cost slightly more than aftermarket options but carry no compatibility risk.

Hyve Technologies offers +2 and +5 extensions with a different aesthetic design. Their extensions are polymer-based and lighter than aluminum alternatives. Some shooters prefer the look; others report that polymer extensions wear faster over time with heavy use.

Springer Precision makes extensions in +2, +3, and +5 configurations. Their designs often include witness holes so you can see the round count from outside the magazine. Springer Precision extensions tend to be in the mid-range price bracket.

Holster and carry compatibility issues

The most common problem with magazine extensions is that they make the magazine longer, and a longer magazine may not fit in your current holster. If you carry your P365 in a pocket holster or a tight-fitting IWB (inside-the-waistband) holster, an extended magazine may stick out or prevent the holster from seating properly. Test your setup before you rely on it.

Some holster makers offer extended magazine versions of their designs, or you can purchase a new holster that is cut for a longer magazine. Alternatively, you can carry an extended magazine as a spare reload in your pocket or bag while keeping a standard 10-round magazine in your carry holster. This gives you the extra capacity without changing your daily carry setup.

If you use a light or laser attachment on your P365, check that the extended magazine does not interfere with the attachment when you insert or remove the magazine. Most attachments sit high enough that this is not an issue, but it is worth confirming with your specific setup.

Reliability and feeding concerns

Magazine extensions are generally reliable, but feeding problems can occur if the extension is not installed correctly or if the magazine spring is worn. The most common issue is that rounds do not feed smoothly from the extended portion of the magazine, usually because the follower is not sitting flat or the extension is not fully seated on the magazine tube.

To avoid feeding problems, disassemble the magazine and inspect the follower for cracks or warping. If the follower looks damaged, replace it with a new one before installing the extension. Load the magazine fully and manually cycle several rounds through your pistol to test feeding before you carry it. If rounds still do not feed smoothly, try a different brand of extension or contact the manufacturer for support.

Some shooters report that extended magazines are slightly less reliable when the magazine is fully loaded, because the spring is compressed more tightly. This is rare, but if you experience it, you can load one round fewer than the extension's rated capacity to reduce spring pressure.

Cost and where to buy

Magazine extensions typically cost between $15 and $40 each, depending on the brand and the number of rounds added. SIG Sauer OEM extensions are usually at the higher end of that range. Aftermarket brands like Taran Tactical, Hyve, and Springer Precision fall in the middle. You can find them at online retailers that sell firearm accessories, gun shops, and some large sporting goods stores.

Buying multiple extensions at once is common because many shooters want to extend all their P365 magazines or keep spares. Some retailers offer small discounts for buying two or more. Check the return policy before you buy, in case the extension does not fit your holster or does not feed reliably in your specific pistol.

Frequently Asked Questions

Will a P365 extension fit a P365 XL magazine?

No. The P365 XL uses a different magazine design and baseplate. Extensions made for the standard P365 will not fit the XL magazine. SIG Sauer and aftermarket makers produce separate extensions for the XL, so check the product description before you buy.

Can I use an extended magazine in my P365 SAS or P365 Macro?

The P365 SAS and P365 Macro use the same magazine as the standard P365, so standard P365 extensions will fit. However, the Macro is a shorter pistol, and a longer magazine may look disproportionate or affect how the gun handles. Test the fit and feel before you carry it.

Do I need to replace the magazine spring when I add an extension?

No. The original spring and follower work with the extension. The spring is designed to handle the extra compression from the additional rounds. If you experience feeding problems, the spring may be worn and should be replaced, but this is not caused by the extension itself.

What happens if the extension comes loose during shooting?

If the extension is properly installed, it will not come loose during normal shooting. The baseplate holds it in place. If it does come loose, stop shooting, remove the magazine, and reinstall the extension, making sure it is fully seated. Loose extensions are usually a sign of improper installation or a worn baseplate.

Can I carry a loaded extended magazine in my pocket?

Yes, but the longer magazine may be uncomfortable or obvious in a pocket. Many shooters carry an extended magazine as a spare reload in a magazine pouch on their belt instead. If you do pocket carry a loaded extended magazine, use a dedicated magazine pouch to protect the rounds and keep the magazine find.