Transform Your Compact Glock® with Full-Size Capacity
The Glock® 19 and 23 sit at the center of more carry rigs, competition holsters, and duty setups than any other compact pistol on the market — trusted for their balance of size, capacity, and reliability. The Shield Arms Glock® 19/23 +5/4 Magazine Extension pushes that balance further, adding 5 rounds to your Glock® 19 or 4 rounds to your Glock® 23 without requiring a new gun, a new holster, or a permanent modification to your firearm.
The extension ships with a +10% power spring engineered to drive reliable feeding at the increased stack height. A unique easy-access floor plate lets you open and service the spring and follower in the field without pulling the extension off the magazine body. Machined index cuts on the extension body give you a positive, non-slip purchase when stripping a magazine under stress. All of it CNC-machined from billet 6061 aluminum, finished in a Type 2 anodized coating, and built in the USA.
Key Features
+5/4 round capacity increase: Adds 5 rounds to Glock® 19 (9mm) and 4 rounds to Glock® 23 (.40 S&W) OEM magazines
Ships with a +10% power spring: Included upgraded spring ensures reliable feeding at the increased capacity — no separate spring purchase required
Unique easy-access floor plate: Service the spring and follower in the field without removing the extension from the magazine body
Index cuts for improved grip: Machined cuts on the extension body provide a positive, non-slip purchase when drawing from a magazine pouch under stress
Billet 6061 aluminum construction: CNC-machined for consistent tolerances, lightweight durability, and long-term corrosion resistance
Type II Anodized Finish: Hard, abrasion-resistant surface treatment with a consistent matte appearance
Universal generation compatibility: Works with Glock® 19 and 23 Gen 3, 4, and 5 pistols using OEM magazines
OEM Glock® magazine compatibility: Designed and tested exclusively for factory Glock 19/23 magazines
Compatible with most aftermarket flared magwells: Works with popular magwell options for competition and duty setups
Drop-in installation: No permanent modifications to your magazines or firearm required
Made in the USA: Precision-machined domestically for consistent quality control
Why the Included +10% Power Spring Matters
Adding rounds to a magazine isn't just a geometry problem — it's a spring tension problem. Stretching OEM magazine spring geometry across a longer stack can result in inconsistent feeding pressure, especially in the top rounds. Shield Arms includes a +10% power spring with every Glock® 19/23 extension, engineered specifically for the increased capacity configuration. The result is reliable round presentation from the first round to the last, without any additional parts to source or install.
Why the Easy-Access Floor Plate Matters
Standard magazine extensions require full removal from the magazine body before the spring and follower can be reached for cleaning or inspection. The Shield Arms easy-access floor plate opens independently — exposing the internals without disturbing the extension's fit on the magazine. For competition shooters who maintain multiple magazines between stages and for duty users who field-strip their gear regularly, this means faster cleaning, faster inspections, and a more serviceable system wherever you need it.
These are RESTRICTED in some states. Your order will be CANCELLED if you are in a high-capacity restricted state.(State Restrictions)
DISCLAIMER: This product is not manufactured, authorized, endorsed, or warranted by GLOCK. GLOCK does not warrant or represent that this product is compatible with GLOCK pistols.
I shot my first match with these extensions. Everything worked as designed. My only complaint is the ease of removal from the mag body for cleaning. Small Alan head screws.
Warranty Information
Any warranty issues with this product must be handled directly with Shield Arms. (Manufacturer's Warranty)
