ProMag PM237B Magazine Adapter Block - 9mm AR-15 Lower Polymer

The ProMag PM237B Magazine Quick Change Adapter Block transforms standard AR-15 lower receivers to accept 9mm pistol caliber carbine magazines. This polymer adapter block eliminates the need for dedicated 9mm lower receivers while maintaining reliable feeding and extraction. Professional armorers and competitive shooters rely on this conversion solution for its consistent performance and drop-in installation.

What Makes This Different

Unlike permanent modifications or expensive dedicated lowers, the PM237B provides a reversible conversion that preserves the original AR-15 platform. The precision-molded polymer construction maintains proper magazine geometry while reducing weight compared to aluminum alternatives. Installation requires no permanent modifications to the host firearm, allowing users to switch between rifle and pistol caliber configurations as needed.

Key Features

• Drop-in installation compatible with mil-spec AR-15 lower receivers
• Accepts standard Glock-pattern 9mm magazines up to 33-round capacity
• Reinforced polymer construction withstands repeated magazine insertions
• Black finish matches standard AR-15 components
• Maintains proper magazine catch engagement and release function
• No permanent modifications required to host firearm
• Compatible with most aftermarket magazine releases

The adapter block performs reliably in competitive shooting environments where rapid magazine changes are critical. Law enforcement agencies have adopted similar conversion systems for training applications using less expensive 9mm ammunition. The polymer material resists impact damage during tactical reloads and maintains dimensional stability across temperature ranges. Range testing demonstrates consistent feeding with hollow point and ball ammunition types.

Technical Specs

• Material: High-impact polymer construction
• Finish: Matte black polymer
• Compatibility: Mil-spec AR-15 lower receivers
• Magazine Compatibility: Glock-pattern 9mm magazines
• Installation: Drop-in, no gunsmithing required
• Weight: Approximately 2.1 ounces
• Manufacturer: ProMag Industries
• Model Number: PM237B

This adapter block represents a cost-effective solution for shooters seeking 9mm AR-15 capability without purchasing dedicated components. The proven design has established reliability standards in the pistol caliber carbine market. Professional installations take minutes rather than hours, making this an efficient upgrade for multiple platforms.