Warne Magazine Extension Black, +3 (9mm Luger), +4 (40S&W), for S&W M&P 9/40 3306

Warne Magazine Extension — Black, +3 (9mm Luger) / +4 (.40 S&W), Fits S&W M&P 9/40 (3306 • UPC 656813108084) Add capacity. Keep reliability. The Warne Magazine Extension for Smith & Wesson M&P 9/40 boosts your factory mag to +3 rounds in 9mm or +4 rounds in .40 S&W without compromising confidence on the range or during duty and competition. Built from durable, precision-machined material with a matte black finish, this low-profile base pad locks up tight, resists hard use, and maintains consistent feeding with the right spring setup. Why Shooters Choose the Warne +3/+4 Extension More rounds, same footprint: Gain +3 (9mm) or +4 (.40 S&W) capacity while preserving a compact, carryable profile that still fits most mag pouches. Purpose-built for M&P 9/40: Designed to fit S&W M&P 9 and M&P 40 magazine bodies (select full-size/compact mags—see compatibility notes). Reliable lock-up: Positive retention system helps prevent walk-off under recoil, drops, and high-round-count training. Fast reloads: Extended base pad improves purchase during mag changes—especially with gloves or in wet conditions. Durable construction: Engineered to handle duty use, USPSA/IDPA training, and everyday range abuse. Clean, black finish: Low-glare black exterior blends with factory aesthetics for a professional, OEM-like look. Key Features at a Glance Model: 3306 Finish/Color: Black Capacity Increase: +3 rounds (9mm Luger) • +4 rounds (.40 S&W) Fitment: S&W M&P 9/40 (magazine-dependent; see notes) Use Case: Competition • Training • Range • Duty/EDC (where legal) UPC: 656813108084 Performance Benefits You’ll Notice Quicker indexing: The slightly extended base gives your hand a consistent reference point out of the pouch or pocket. Improved balance: Added base weight promotes confident seating on closed slides and consistent drops during reloads. Field-serviceable: Simple on/off design supports fast cleaning and spring swaps. Pro Tip: Always verify your magazine spring is appropriate for an extended base (many shooters upgrade to a stronger spring for optimal feeding and slide lock). Compatibility & Fit Notes Designed for Smith & Wesson M&P 9 and M&P 40 double-stack magazines. Capacity claims: +3 (9mm Luger), +4 (.40 S&W), assuming standard-length magazines in good condition with compatible follower/spring. May not fit Shield/Shield EZ/Single-stack models or certain compact/10-round restricted magazines. Check your mag’s baseplate style, body windowing, and locking plate before installation. Installation Overview Unload & clear the firearm and workspace. Depress the locking plate button and remove the factory floorplate carefully (springs are under tension). Inspect the follower & spring; replace with a heavy-duty spring if recommended. Slide on the Warne extension until it locks positively. Function-check: Manually cycle rounds (dummy rounds preferred), verify feeding, slide lock, and drop-free operation. Range-validate with your carry/competition ammo. Always follow manufacturer instructions. If unsure, consult a qualified armorer. Specs Brand: Warne Product Type: Magazine base pad/extension Color: Black Added Capacity: +3 (9mm), +4 (.40 S&W) Firearm Platform: S&W M&P 9/40 (magazine dependent) Model Number: 3306 UPC: 656813108084 Compliance & Best Practices Know your laws: Magazine capacity limits vary by jurisdiction. Confirm legality for your area and intended use. Competition rules: Some divisions restrict overall mag length or capacity. Check your USPSA/IDPA rulebook before match day. Maintenance: Periodically inspect the retention screw/pin (if present) and spring condition; replace worn parts promptly. SEO Metadata (Merchant-Ready) SEO Title: Warne Magazine Extension for S&W M&P 9/40 — Black, +3 (9mm) / +4 (.40 S&W), Model 3306 Meta Description (≤160 chars): Boost your S&W M&P 9/40 mags with Warne’s black extension: +3 (9mm) or +4 (.40 S&W). Durable, secure fit, competition and range ready. Model 3306. Target Keywords: Warne magazine extension M&P, M&P 9mm +3 basepad, M&P 40 +4 extension, black mag extension 3306, 656813108084, S&W M&P mag upgrade Alt Text (Images): “Warne black magazine extension for S&W M&P 9/40, +3 9mm and +4 .40 S&W, model 3306.” FAQ Q: Will this work with my M&P Shield or Shield Plus? A: No. This extension is designed for M&P 9/40 double-stack mags, not Shield/Shield Plus single-stack magazines. Q: Do I need a new spring? A: Many users run a stronger magazine spring for best reliability with added capacity. Follow Warne’s guidance or use a reputable spring upgrade. Q: Will it fit 10-round restricted magazines? A: Often not. Extensions may be incompatible with reduced-capacity bodies and may be illegal in some locations. Verify before purchase. Q: Is the finish durable? A: Yes—the black, low-glare finish is designed to resist sweat, solvent, and everyday range wear. Q: Can I install it myself? A: Yes, with basic tools and care. If you’re unfamiliar with mag disassembly, a gunsmith or armorer can install it quickly. Upgrade your S&W M&P 9/40 with the Warne Magazine Extension (3306) and get the extra rounds, faster reloads, and confident handling you want—without sacrificing reliability or style. The End