S&W M&P 9mm 23-Round Magazine

The Smith & Wesson factory 23-round M&P 9mm magazine is the highest-capacity factory option for M&P full-size and compact pistols, and the standard high-capacity choice for the M&P FPC carbine. The stainless steel body carries a corrosion-resistant finish, backed by a high-tensile steel spring and polymer follower that feed reliably through the full 23-round capacity. Numbered witness holes on both sides provide a fast round count.

A polymer grip adapter spacer is included. On the M&P FPC carbine, this adapter ensures a flush fit with the FPC's extended magazine well housing, preventing any gap between the magazine base and the receiver. The magazine functions in M&P FPC builds whether the platform is running the factory M&P magazine well or has been configured with the Glock-pattern well adapter.

The 23-round capacity adds six rounds over the standard full-size M&P 17-round magazine, meaningful in defensive use and significantly reducing reload frequency during training. At around $50, it costs moderately more than the standard 17-round option and reflects the extended capacity stainless construction.