ProMag AR-15 Conversion Rifle Magazine 9mm Luger 40/rd

Converting an AR-15 to fire 9mm opens up cost-effective practice and training options for shooters in Mountain View and throughout the Bay Area. This 40-round magazine pairs with dedicated conversion uppers to deliver reliable feeding in your existing platform. Before any firearm purchase or modification, familiarize yourself with California firearm laws to ensure your setup stays legal.

High-capacity 9mm feeding for AR conversions

The 40-round capacity makes this magazine practical for range sessions and competitive shooting where magazine changes eat into your time. ProMag engineered these specifically for 9mm Luger feeding through AR-15 conversion uppers, so compatibility is straightforward if you're already running that platform. Need help with California purchasing rules? Browse our California-compliant handgun catalog for alternative options. Double-stack design keeps the profile manageable while maximizing rounds downrange. Visit our gun shop in Sunnyvale for our full catalog.

Frequently asked questions

Will this magazine work in standard 5.56 NATO AR-15 magazines wells?

No. This magazine is designed specifically for 9mm Luger conversion uppers that use dedicated magazine wells. Standard AR-15 wells won't accept this 9mm conversion magazine.

How reliable is the ProMag COLA38 for competition use?

Many shooters use ProMag conversion magazines for USPSA and 3-gun events without issues. Test-fire several magazines before match day to ensure your specific gun feeds reliably with your ammunition.

What is an FFL transfer in California?

An FFL transfer is when a federally-licensed dealer like TacticCAL receives a firearm shipped from another seller and processes California's required DROS paperwork to legally transfer it to you. Looking for gun shop Oakland? Visit us in Sunnyvale.