ProMag RM40FDE StandardFlat Dark Earth Detachable with Roller Follower 40rd for 5.56x45mm NATO AR-15
- Capacity-Rounds:
- 40
- Type:
- Magazines
- Firearm Group:
- AR Platform
- Caliber-Gauge:
- 223 Remington / 5.56 NATO
- Finish-Color:
- Flat Dark Earth
- Model:
- Standard
- Material:
- DuPont Zytel Polymer
- Model Fit:
- AR-15
The ProMag RM40FDE is a 40-round AR-15 magazine built for shooters who need reliable high-capacity feeding without breaking the bank. Whether you're running a training day, running suppressive fire at the range, or stocking up for serious use, this magazine delivers the round count when standard 30-rounders aren't enough. Made in the USA and chambered for 5.56x45mm NATO, the RM40FDE combines practical capacity with proven reliability in a clean Flat Dark Earth finish that fits modern rifle builds.
ProMag engineered these magazines with precision manufacturing as the foundation. The springs are wound from heat-treated chrome silicon wire—the good stuff—and every assembly step is inspected and verified to keep quality consistent unit to unit. That attention to detail matters when you're counting on feeding reliability downrange. The roller follower design supports smooth, consistent round presentation, and the durable polymer construction keeps weight minimal while standing up to the wear and tear of regular use.
You get a lifetime guarantee against manufacturer defects, which underscores ProMag's confidence in their product. For AR shooters looking to extend their shooting window between magazine changes or who simply prefer the peace of mind that comes with extra capacity, the RM40FDE is a no-frills, dependable choice.
Key Features
- 40-round capacity for extended shooting sessions
- Heat-treated chrome silicon magazine springs for long-term reliability
- Roller follower for smooth round feeding
- Durable polymer construction keeps weight low
- Made in the USA
- Flat Dark Earth finish
- Lifetime guarantee against manufacturer defects
Specifications
| Brand | Pro Mag |
| Capacity | 40 rounds |
| Caliber Compatibility | 5.56x45mm NATO |
| Platform | AR-15 |
| Follower Type | Roller |
| Material | Durable polymer |
| Finish | Flat Dark Earth (FDE) |
| Country of Origin | USA |
| Warranty | Lifetime guarantee against manufacturer defects |
Frequently Asked Questions
Will this 40-round magazine work in my AR-15?
Yes. The ProMag RM40FDE is designed for AR-15 platforms and is chambered in 5.56x45mm NATO, the standard cartridge for modern AR-15 rifles.
What's the advantage of a roller follower?
The roller follower design helps ensure smooth, consistent feeding of rounds from the magazine into the chamber, contributing to reliable operation during shooting.
Is this magazine made in the USA?
Yes. ProMag manufactures this magazine in the USA and backs it with a lifetime guarantee against manufacturer defects.
What's included in the package?
You receive the ProMag RM40FDE 40-round magazine. The specifications provided do not detail any additional accessories or components included with the purchase.

