Customer-Driven Innovation: The Story Behind Our Mag Guts-Compatible P365X/XL Magazine Adapter

Posted by Simon Stevens on May 22nd 2025

If you're a SIG Sauer P365X or P365XL owner looking to optimize your magazine setup, you’ve probably come across a maze of mag types, base pads, and compatibility notes. We're here to simplify that journey and introduce you to our custom magazine base pad adapters — designed for those who want reliability, compatibility, and performance without increasing mag capacity.

Sometimes, the best products come from customer feedback — and this one is no exception. In early 2025, a customer reached out to us with a unique request. They had been using one of our 12-round magazine adapters for the SIG Sauer XMacro grip module, designed to let standard P365X and P365XL magazines work in the larger XMacro frame. But they wanted something more.

Specifically, they were looking for a way to integrate the Mag Guts™ spring system into our adapter — to gain the benefits of easier loading and increased capacity (in states where that’s allowed).

We were intrigued.

From DIY Prototype to Production Reality

What made this request even more interesting? The customer had already taken matters into their own hands — literally. They had hand-modified one of our adapters to prototype their idea and even sent over CAD mockups to help illustrate the concept.

As it happened, the timing was perfect. We were just about to begin another production run of our 12-round adapters and had fresh billet aluminum in the shop, ready to be CNC-machined. It seemed like the perfect timing — but once we got into the details, we realized this wasn’t going to be a simple tweak.

The Engineering Challenge

To make this new adapter work with the Mag Guts™ system, we needed to accommodate a different internal geometry — especially for the longer, base section of the Mag Guts spring.

But here’s the tricky part: we couldn’t compromise our high machining standards or wall strength. These adapters need to withstand hard use, and unlike polymer base pads or even some OEM options, our CNC-machined aluminum parts are built to survive drops on concrete, hard floors and anything else the range throws at them.

Our solution? A smart internal redesign that features a deep, angled floor to fit the spring system while maintaining a robust wall thickness for durability.

Reinventing the Process

To pull it off, we had to rethink our machining process:

  • We adjusted how the adapters are held in the second CNC operation to prevent deformation.

  • We developed entirely new fixtures to ensure perfect precision with every part.

  • And because of the thinner internal walls and deeper cuts, these adapters take significantly longer to machine than our standard base pads.

It was a lot more work than expected — but the results were absolutely worth it.

Compatibility Notes

If you're running a 10-round dimpled P365X or P365XL magazine (which shares the same tube length as the 12-round mags), you're in luck. This adapter will fit. But it’s important to note:

Using this adapter on a dimpled 10-round mag will NOT increase capacity — the limitation is built into the mag body tube, not the base pad.

That said, if you’re using Mag Guts™ internals in a 12-round magazine body, this adapter is designed to work flawlessly, blending innovation and durability with user-driven design.

Why It Matters

This project was a reminder of why we love what we do: building rugged, precision-engineered parts that solve real problems for real shooters — and doing it right, even when the solution isn’t simple.

Every adapter is CNC-machined in the USA, from billet aluminum, anodized for durability, and backed by our lifetime warranty against design and manufacturing defects (cosmetic wear from heavy use not included, because let’s face it — you’re gonna train hard).

Got feedback or ideas like this one? Our inbox is always open. Because sometimes, the best innovations come from you.

Let’s break it down.

What These Adapters Do

Our mag base pad adapters are built to work with SIG Sauer P365X and P365XL 12-round magazines — or the dimpled 10-round mags that use the same tube length. These adapters are precisely machined to fit and function seamlessly with Mag Guts™ internals. They do not increase the magazine’s capacity but do allow your mags to function properly in larger grip modules like the XMacro and other competition or carry builds.

Compatibility: What Works and What Doesn’t

These base pads are incredibly versatile, but only if you're using the right magazine type.

✅ Compatible With:

  • Original 12-round P365X/XL magazines

  • 10-round dimpled mags (same length as 12-round mags)

  • Mag Guts™ upgraded springs

  • Grip modules including XMacro, Tacops, Sig Sauer OEM magwells, and many aftermarket magwells

❌ NOT Compatible With:

  • Newer 10-round magazines with plastic extenders

  • Short 10-round tubes that do not share the 12-round length

  • Magazines without Mag Guts™ internals

Pro Tip: If your 10-round mag has two dimples pushed into the sides, it’s the same length as a 12-round mag and these adapters will fit — but your capacity stays at 10.

Low Profile vs. Extended: Choose Your Style

We now offer two versions of our base pad adapters to suit different use cases:

  • Low Profile – Minimalistic, flush-fitting, and designed to disappear into magwells. Ideal for concealed carry.

  • Extended – Adds grip and a bit of weight. Extends past most magwells and is perfect for competition shooters or those wanting faster reloads.

Installation Tips

Installing your Mag Guts™ spring and our adapter may require a little finesse. Here's what you need to know:

  • The spring installs at an angle due to internal machining – a small flathead screwdriver helps a lot.

  • You should see the retainer button through the hole in the adapter base.

  • The base may feel slightly loose when empty, but it will lock up solidly once the mag is loaded — totally normal.

  • The deeper, angled machining makes installation a bit more involved than traditional pads, but it’s worth it for the precision fit.

Built to Last

Each adapter is:

  • Precision-machined in the USA from billet aluminum

  • Anodized for a robust, wear-resistant finish

  • Backed by a lifetime warranty against design or manufacturing defects

Cosmetic wear from drops or use on rough surfaces like concrete isn’t covered, but function always is.

Final Thoughts

These base pads are the ideal upgrade for anyone looking to blend Mag Guts™ performance with modern grip modules like the XMacro. Whether you're carrying every day or shooting competition, you’ll appreciate the solid lockup, clean design, and lasting durability.

Before ordering, double-check your mag dimensions against the images on our product page. If you’re using a pinned 10-round mag with dimples, you’re good to go — just don’t expect extra rounds. Functionality is the goal here.

Ready to upgrade? Check out the full lineup of Sig Sauer P365 base pad upgrades and adapters on our shop and experience the difference precision engineering makes.

* Mag Guts (TM) - All trademarks used are the property of their respective owners, and their use here does not imply endorsement

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