Warne 3306 Magazine Extension S&W M&P 9/40 +3/+4 Round Black

The Warne 3306 Magazine Extension transforms standard S&W M&P 9/40 magazines into higher-capacity solutions for competition and duty use. This precision-engineered extension adds three rounds to 9mm magazines and four rounds to .40 S&W magazines without compromising reliability or function.

What Makes This Different

Unlike universal extensions that require modification, the Warne 3306 installs directly onto factory M&P magazines with a secure press-fit design. The extension maintains the original magazine's profile while extending length by exactly 0.75 inches. CNC-machined from aircraft-grade aluminum and finished in durable black anodizing, this extension withstands thousands of loading cycles without wear.

Key Features

• Increases capacity by +3 rounds (9mm) or +4 rounds (.40 S&W)
• Direct fit for S&W M&P 9mm and .40 S&W factory magazines
• CNC-machined aluminum construction with Type III hard anodizing
• 0.75-inch length extension maintains holster compatibility
• Tool-free installation with secure press-fit attachment
• Maintains original magazine spring tension and feed geometry
• Compatible with all M&P 9/40 variants including Compact and Full Size

Field testing demonstrates consistent feeding across various ammunition weights and manufacturers. The extension's internal geometry preserves the magazine's original feed angle, preventing jams common with poorly designed alternatives. Competition shooters report reliable function through extended strings of fire, while the added capacity proves valuable for duty applications where reload opportunities may be limited.

Technical Specs

• Material: 6061-T6 aluminum alloy
• Finish: Type III hard coat anodizing, black
• Length Extension: 0.75 inches
• Weight: 0.8 ounces
• Compatibility: S&W M&P 9mm and .40 S&W factory magazines
• Capacity Increase: +3 rounds (9mm), +4 rounds (.40 S&W)
• Installation: Tool-free press fit
• Country of Origin: USA

The Warne 3306 delivers proven capacity enhancement without sacrificing the reliability that makes M&P pistols trusted by professionals worldwide. Quality construction and precise engineering ensure this extension performs when it matters most.