Smith & Wesson M&P Magwell Compatible Magazine Extension by Henning

Add Capacity to Your M&P — Without Losing Your Magwell

Most M&P shooters hit the same wall: you want a magazine extension for more rounds, but you also want a magwell for faster reloads — and most extensions force you to choose one or the other. The Henning extension solves that. It's engineered to work with a magwell installed, so you get both the capacity bump (17 up to 23 rounds on a factory spring, or 24+1 with an MBX or CSRG follower and spring) and the reload speed of a funneled mag well. CNC-machined from 6061-T6 billet aluminum and gauged to the USPSA 141.25mm limit, it's legal and ready for Carry Optics, Limited Optics, Limited, and Open.

The Henning Group Magazine Extension Kit for  Smith & Wesson M&P 9mm increases magazine capacity from 17 to 23 rounds!  The design of our extension is a true extension of the internal shape of the factory magazine tube. Combined with a stainless steel, 13-coil magazine spring it is a proven and reliable solution. Our Smith & Wesson M&P 9mm magazine extension is CNC machined from 6061-T6 billet aluminum. This extension fits the USPSA 141.25mm gauge, and is legal for Carry optics, Limited Optics, Limited & Open divisions in USPSA. 

Our latest design includes numbering dots, serrations for light side grab and a reinforced wall thickness. 

We have three options for springs:

A. Henning Group spring (using factory follower). Installed on a 17 round mag, our spring ensures proper function.

B. MBX Follower and Spring increases capacity from 17 to 24 + 1. No Lock Back! Only for 17 round mags.

C. CSRG Competition Follower and Spring increases capacity from 17 to 24 + 1. No Lock Back! Only for 17 round mags.

Works with all magwells we have tried, including the following:
-Ed Brown
-S&W Factory Magwell. *Some grip retaining pins may require modification for the mag to drop free*

*Does Not Fit Competitor HD - Metal Frame Factory Magwell.*
Will Function with Springer Precision Metal Frame Magwell and Floyds Custom Shop Competitor Magwell

MBX & CSRG Aftermarket Follower Kits does NOT LOCK slide back on empty.

To reach the full 24+1, the extension needs the right follower and spring — a factory spring gets you to 23, while an MBX or CSRG kit maxes it out. Ben Stoeger Pro Shop stocks this extension alongside S&W M&P magazines and mag kits, additional M&P added-capacity basepads, and double-stack mag pouches to carry your extended mags on the belt. Fast shipping from our Texas warehouse, and our team runs the M&P in competition — if you're not sure which spring and follower combo fits your goal, just ask.

MBX "Ultra Max" Spring & Follower

*Note This Product will not lock slide back on last round fired

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