Aero Precision Mil-Spec Carbine Buffer Kit W/ H Buffer For Ar-15 Black

Short-stroke gas systems on modern AR-15s—especially in pistol-length and carbine builds—can push more gas back into the receiver than a standard rifle needs, accelerating wear on bolt carriers, firing pins, and other internals while hammering your shoulder with extra recoil. The Aero Precision Mil-Spec Carbine Buffer Kit with H Buffer gives you a straightforward way to dial in your AR's operating system. This kit pairs a heavier buffer with mil-spec internals so you can tame overgassing without replacing your entire setup or hunting for parts separately.

Aero Precision engineered this kit around the idea that one buffer doesn't fit every build. The H (Heavy) buffer in this kit weighs 4 ounces—heavier than a standard 3-ounce buffer—which slows the bolt carrier's rearward travel and reduces cyclic rate. The result: less felt recoil, lower impulse on your action, and longer life for small parts. If you're running a tight AR-15 build or dealing with velocity spikes, this is a practical upgrade that costs far less than chasing accuracy problems or replacing worn internals down the road.

The kit ships complete: a mil-spec buffer tube machined from 7075-T6 aluminum (same material as mil-spec uppers and lowers), a carbine-length buffer spring, an end plate, and a castle-lock nut. The tube is drilled for six-position adjustable stocks, so you're not locked into one cheek weld. All parts are mil-spec, which means they'll work with any standard AR-15 lower and any six-position stock on the market.

Whether you're building a short-barreled rifle, tuning a competition gun, or just tired of beating yourself up at the range, a heavier buffer is one of the easiest tuning moves you can make. This kit makes it a single purchase instead of cobbling together separate components.

Key Features

• H (Heavy) buffer at 4 ounces—heavier than standard to reduce overgassing and recoil impulse
• Mil-spec 7075-T6 aluminum buffer tube with six-position adjustment slots
• Complete kit includes buffer spring, end plate, and castle-lock nut—no additional parts needed
• Direct fit for AR-15 platform rifles with standard receivers
• Easy tuning option for short gas systems and pistol-length builds

Specifications

Frequently Asked Questions

Will this buffer kit work with my AR-15 lower receiver?

Yes. This is a mil-spec carbine buffer kit designed to fit any standard AR-15 lower. The tube threads in like any other carbine-length system.

What's the difference between an H buffer and a standard buffer?

The H (Heavy) buffer in this kit weighs 4 ounces, compared to a standard buffer at 3 ounces. The extra weight slows the bolt carrier's rearward travel, reducing recoil impulse and cyclic rate—a simple way to manage overgassing on short gas systems.

Can I use a six-position adjustable stock with this buffer tube?

Yes. The tube is drilled and slotted for six-position stocks, which are the industry standard for AR-15s.

Does this kit come with everything I need to install it?

Yes. The kit includes the buffer tube, H buffer, buffer spring, end plate, and castle-lock nut. You'll need a castle-nut wrench to tighten it down, but all the major components are included.