MAG SIG P365 X-MACRO 21RD BLK

The Sig Sauer MAG SIG P365 X-MACRO 21RD is a factory-spec extended magazine built for shooters who want serious capacity in a modern compact platform. This 21-round 9mm magazine comes standard with the P365-FUSE model and works across the entire P365 lineup—from the standard frame all the way up to the X-MACRO platform. Whether you're running a P365, P365-X, P365-XL, P365-XMACRO, P365-AXG Legion, or P365-FUSE, this magazine delivers reliable feeding and consistent performance right out of the box.

Built with practical shooter features, the magazine includes witness holes along the rear body so you can visually confirm your loaded round count at a glance. An orange follower makes it instantly obvious when the magazine is empty—a small detail that matters in training, competition, or duty use. The black baseplate is engineered to sit flush with P365-XMACRO grip modules (including AXG Legion and FUSE sizes), though it will sit slightly proud on smaller P365 Standard, X, and XL frames due to their shorter grip geometry.

If you're building out spares for your P365 or looking to maximize capacity on your XMACRO, this factory magazine combines proven Sig reliability with thoughtful design touches that make range time and real-world use more efficient.

Key Features

• 21-round 9mm capacity for extended shooting sessions
• Rear witness holes for quick round-count verification
• Orange follower for instant empty-magazine recognition
• Black metal baseplate with proper seating geometry
• Compatible across all P365 models including standard, X, XL, XMACRO, AXG Legion, and FUSE
• Factory Sig Sauer manufactured

Specifications

Frequently Asked Questions

Will this 21-round magazine work with my P365 or P365-X?

Yes. This magazine is compatible with all P365 models, including the standard P365, P365-X, P365-XL, P365-XMACRO, P365-AXG Legion, and P365-FUSE. The baseplate will sit flush with XMACRO grip modules but will have a slight gap when used with Standard, X, and XL frame sizes due to their shorter grip length.

What's the difference between this magazine and others for the P365 lineup?

This is a factory Sig Sauer magazine purpose-built for extended capacity across the entire P365 platform. It includes practical features like rear witness holes for verifying round count and an orange follower to quickly identify when the magazine is empty.

What's included in the box?

You receive the magazine with its black baseplate installed and ready to use.