The Ultimate Firearms Destination for the Gun Lifestyle

Battle Arms Development Offers California Compliant Magazine Conversion

At RECOIL, we review every product fairly and without bias. Making a purchase through one of our links may earn us a small commission, and helps support independent gun reviews. Learn More

Written by Jacki Billings

Battlefield Arms Development announced it will begin offering a California compliant fixed magazine service.

The BAD-MRB, or magazine release block, conversion is accomplished in house by Battlefield Arms employees. Battlefield Arms works some voodoo magic on customers’ stripped lower receiver, mil-spec mag catch, spring, and mag release button to accomplish a fixed magazine design that fits within California’s stringent guidelines for rifle ownership.

Utilizing CNC sorcery, the company drills a hole in the lower receiver to house the BAD-MRB kit — which consists of a spring, blocking pin, and hollow Allen Key screw. Once in place, the BAD-MRB prevents the mag release button from ejecting the mag while the upper receiver is seated on the lower. When the upper is raised, pressure on the plunger is alleviated and the magazine release button functions as normal.


Battlefied Arms Development said its goal is to eventually offer the service as a factory option on its own lowers.

“We will soon (offer the factory option), and so will many other OEM manufacturers who are licensing our design,” Battlefield Arms said in a statement.

The company said the advantage to the BAD-MRB conversion is that it can be reversed, allowing users to take the rifle’s mag release back to its original functioning state.

“You can still use your magazine release as a regular rifle. So, if you ever leave California and you want to return it to (a regular rifle), all it takes is a 3/32-inch Allen Key to remove the shoulder screw that holds the three pieces in and you can use your magazine release just like a regular AR,” the company explained.


Included in the work order is the BAD-MRB mag release block kit, CNC machined time and labor to drill and tap customer supplied lower, machining of inner surface of mag release, and installation and fitting of the BAD-MRB system. All things considered, the cost for the conversion is a meager $75 plus shipping.

Enter Your E-Mail to Receieve a Free 50-Target Pack from RECOIL!

NEXT STEP: Download Your Free Target Pack from RECOIL

For years, RECOIL magazine has treated its readers to a full-size (sometimes full color!) shooting target tucked into each big issue. Now we've compiled over 50 of our most popular targets into this one digital PDF download. From handgun drills to AR-15 practice, these 50+ targets have you covered. Print off as many as you like (ammo not included).

Get your pack of 50 Print-at-Home targets when you subscribe to the RECOIL email newsletter. We'll send you weekly updates on guns, gear, industry news, and special offers from leading manufacturers - your guide to the firearms lifestyle.

You want this. Trust Us.

Add a comment

Your email address will not be published. Required fields are marked *

Subscribe to the Free