$77.61
Availability: In Stock
The ProMag PM237B is a polymer magazine quick change adapter block designed to convert your AR-15 lower receiver to feed 9mm Colt and SMG-type magazines with a 9mm upper. If you've built or own an AR-9 and want the flexibility to swap between magazine types without permanent modifications, this adapter solves that problem. It's one of the few components that lets you transition between common 9mm magazine platforms on the same lower receiver, making it a practical choice for shooters who run multiple caliber uppers or want to experiment with different magazine options at the range or in competition.
The build quality reflects ProMag's reputation for durability. The housing is constructed from high-strength polymer paired with steel internals—including the roller, ejector, and bolt stop hardware. This hybrid approach keeps weight down while maintaining reliability where it counts. Installation is straightforward and actually improved over earlier designs: you don't need to remove your existing bolt stop roll pin to fit the adapter block, which saves time and hassle during setup.
This is a made-in-USA component, and it's sized specifically for 9mm Colt and SMG magazine compatibility. Whether you're setting up a dedicated AR-9 build or adding modularity to an existing lower, the PM237B gives you a quick-change solution without the expense or complexity of swapping lower receivers.
| Product Name | PM237B Polymer Magazine Quick Change Adapter Block |
| Brand | Pro Mag |
| Firearm Compatibility | AR-15 lower receiver |
| Magazine Type | 9mm Colt / SMG magazines |
| Material | High-strength polymer with steel hardware |
| Finish | Black |
| Origin | Made in USA |
Yes, the PM237B is designed specifically for AR-15 and M16 lower receivers. It installs in the magazine well area and requires a 9mm upper receiver to function.
The PM237B is compatible with 9mm Colt and SMG-type magazines, allowing you to use common 9mm magazine designs with your AR-15 platform.
No. The improved design of the PM237B allows installation without removing the existing bolt stop roll pin, making setup faster and easier than earlier adapter designs.
The adapter block is a removable component that installs in the magazine well. It allows you to change magazine platforms without permanent modifications to the receiver itself.
SKU: 115708907 • Width: 3.7in • Height: 1.6in • Depth: 7in • Weight: 0.23oz
Availability: In Stock
The ProMag PM237B is a polymer magazine quick change adapter block designed to convert your AR-15 lower receiver to feed 9mm Colt and SMG-type magazines with a 9mm upper. If you've built or own an AR-9 and want the flexibility to swap between magazine types without permanent modifications, this adapter solves that problem. It's one of the few components that lets you transition between common 9mm magazine platforms on the same lower receiver, making it a practical choice for shooters who run multiple caliber uppers or want to experiment with different magazine options at the range or in competition.
The build quality reflects ProMag's reputation for durability. The housing is constructed from high-strength polymer paired with steel internals—including the roller, ejector, and bolt stop hardware. This hybrid approach keeps weight down while maintaining reliability where it counts. Installation is straightforward and actually improved over earlier designs: you don't need to remove your existing bolt stop roll pin to fit the adapter block, which saves time and hassle during setup.
This is a made-in-USA component, and it's sized specifically for 9mm Colt and SMG magazine compatibility. Whether you're setting up a dedicated AR-9 build or adding modularity to an existing lower, the PM237B gives you a quick-change solution without the expense or complexity of swapping lower receivers.
| Product Name | PM237B Polymer Magazine Quick Change Adapter Block |
| Brand | Pro Mag |
| Firearm Compatibility | AR-15 lower receiver |
| Magazine Type | 9mm Colt / SMG magazines |
| Material | High-strength polymer with steel hardware |
| Finish | Black |
| Origin | Made in USA |
Yes, the PM237B is designed specifically for AR-15 and M16 lower receivers. It installs in the magazine well area and requires a 9mm upper receiver to function.
The PM237B is compatible with 9mm Colt and SMG-type magazines, allowing you to use common 9mm magazine designs with your AR-15 platform.
No. The improved design of the PM237B allows installation without removing the existing bolt stop roll pin, making setup faster and easier than earlier adapter designs.
The adapter block is a removable component that installs in the magazine well. It allows you to change magazine platforms without permanent modifications to the receiver itself.
SKU: 115708907 • Width: 3.7in • Height: 1.6in • Depth: 7in • Weight: 0.23oz