The ProMag AR-15 5.56 NATO 40-round magazine pairs steel and polymer construction to deliver reliable, high-capacity feeding for shooters who want to maximize rounds downrange without constant reloads. Built with a heat-treated steel feed tower finished in black oxide and a shockproof polymer body, this hybrid design balances durability with weight savings—ideal for target shooters, 3-gun competitors, and anyone running extended range sessions or training drills.

ProMag engineered this magazine for smooth, jam-free operation across standard AR-15 platforms. The high-tensile chrome silicon wire spring and injection-molded polymer follower work together to maintain consistent feeding pressure, while the precision-machined magazine catch cutout locks into your receiver with a snug, wobble-free fit that stays put under recoil and handling. Fit is compatible with both Commercial-Spec and Mil-Spec AR-15 receivers, so it'll integrate into most modern and classic builds without guesswork.

This is American-made gear, backed by a lifetime warranty—ProMag stands behind the quality you're getting. Whether you're stocking up for a shooting day, building backup magazines, or just prefer the flexibility of 40-round capacity, this steel/polymer hybrid offers no-nonsense performance at a straightforward value.

Key Features

• 40-round capacity for extended shooting sessions
• Heat-treated steel feed tower with black oxide finish resists corrosion and wear
• Shockproof DuPont Zytel polymer body reduces weight while maintaining durability
• High-tensile chrome silicon wire spring ensures reliable feeding
• Injection-molded polymer follower for smooth operation
• Precision-machined catch cutout fits snug in Commercial-Spec and Mil-Spec receivers
• American-made with lifetime warranty

Specifications

Brand	ProMag
Caliber	5.56 NATO / .223
Capacity	40 rounds
Magazine Type	Steel/Polymer Hybrid
Finish	Black
Feed Tower Material	Heat-treated steel with black oxide finish
Body Material	DuPont Zytel polymer
Spring	High-tensile chrome silicon wire
Follower	Injection-molded polymer
Receiver Compatibility	Commercial-Spec and Mil-Spec AR-15
Country of Origin	USA
Warranty	Lifetime

Frequently Asked Questions

Will this ProMag AR-15 magazine fit my AR-15 receiver?

Yes, it's designed to work with both Commercial-Spec and Mil-Spec AR-15 receivers. The precision-machined catch cutout locks in securely without wobble.

What's the difference between the steel tower and polymer body?

The heat-treated steel feed tower provides durability and corrosion resistance at the point where rounds feed into the chamber, while the shockproof polymer body keeps the overall magazine light and impact-resistant. It's a hybrid approach that combines the strength you need where it matters most with the weight savings of polymer construction.

Is the ProMag 40-round magazine suitable for 3-gun or competition shooting?

Yes. The high-tensile spring and polymer follower deliver jam-free operation, and the 40-round capacity is practical for target-rich stages and extended range work. The snug fit under recoil ensures stability during rapid fire.

What warranty does this magazine come with?

ProMag backs this magazine with a lifetime warranty, covering defects in materials and workmanship.