Upgrade your large-frame AR with reliability you can count on using the CMMG Buffer Assembly, MK3 AR-10, Carbine, Silver (Part #: 38CA929 | UPC: 815835015064). Built specifically for CMMG’s MK3/AR-10–style platforms, this carbine-length buffer assembly is engineered to handle the increased mass, recoil, and energy of .308 Winchester and other AR-10 calibers—all while delivering smoother cycling and long-term durability.
Whether you’re completing a new AR-10 build, refreshing a high-round-count rifle, or upgrading from a mismatched buffer setup, this CMMG MK3 carbine buffer assembly helps ensure your rifle runs like it should.
Purpose-Built Carbine Buffer for MK3 / AR-10 Platforms
Unlike standard AR-15 buffers, the CMMG MK3 AR-10 Carbine Buffer Assembly is designed around the unique dimensions and recoil characteristics of large-frame AR rifles. It’s tuned for:
.308 Win / 7.62 NATO and similar calibers
MK3 / AR-10 pattern rifles using a carbine receiver extension
Increased bolt carrier mass and higher recoil impulse compared to 5.56
This isn’t a generic “one size fits most” buffer—it’s designed specifically to support the operation of your AR-10–style carbine.
Smoother Cycling & Enhanced Reliability
The buffer assembly is a critical component in your recoil system. When properly matched to your platform, it helps:
Reduce bolt speed for more controlled, consistent cycling
Minimize felt recoil and muzzle movement, improving follow-up shots
Decrease wear and stress on your bolt, lugs, and receiver extension
Improve reliability under rapid fire and varied ammo loads
If you’ve experienced harsh recoil, inconsistent ejection, or premature parts wear with a mismatched buffer, upgrading to a dedicated MK3 AR-10 carbine buffer can make a noticeable difference.
Carbine-Length Configuration
This carbine-length buffer assembly is designed to work with AR-10/MK3 carbine receiver extensions (buffer tubes), making it ideal for:
Collapsible / adjustable stocks on AR-10 rifles
Compact, versatile setups where you want a shorter, adjustable stock
Duty, hunting, or sporting rifles that benefit from a carbine-style recoil system
Pair it with the appropriate MK3/AR-10 carbine buffer tube and spring for a properly tuned large-frame build.
Precision-Machined Silver Finish
The silver buffer body is built for long-term durability inside your receiver extension:
Precision-machined construction for consistent weight and travel
Smooth surface finish to help ensure reliable movement in the tube
Silver color for easy identification when working on multiple rifles or buffer systems
While you won’t see it once the rifle is assembled, the quality and finish show in the way your rifle cycles and feels.
Ideal for Builds, Upgrades, and Replacements
The CMMG MK3 AR-10 Carbine Buffer Assembly is a smart choice for:
New AR-10 builds using CMMG MK3 or compatible large-frame receivers
Upgrading from AR-15 buffers that aren’t properly matched to .308 platforms
Replacing worn or damaged buffers in high-use rifles
Armorers and builders who want reliable, brand-name components in their recoil systems
Starting with correctly spec’d parts helps avoid the trial-and-error headaches that can come with tuning large-frame ARs.
Designed by a Trusted AR Manufacturer
CMMG is widely recognized for its innovative AR platforms and reliable parts, from PCCs to .308 rifles. Their MK3 AR-10 Carbine Buffer Assembly benefits from that same design and manufacturing experience:
Built to work with CMMG MK3 receivers and compatible AR-10–style platforms
Backed by a manufacturer known for serious, hard-use firearms and components
Ideal for shooters who want to match components from a single, trusted brand
If you’re building around CMMG’s MK3 platform, it makes sense to use a buffer assembly designed for it from the start.
Key Features & Specifications
Brand: CMMG
Product Type: Buffer Assembly
Platform: MK3 / AR-10–style rifles
Configuration: Carbine-length buffer
Color/Finish: Silver
Intended Use: Large-frame AR rifles using carbine receiver extensions
Part Number: 38CA929
UPC: 815835015064
Why Choose the CMMG MK3 AR-10 Carbine Buffer Assembly?
When you choose the CMMG Buffer Assembly, MK3 AR-10, Carbine, Silver (38CA929), you’re getting:
A buffer specifically tuned for AR-10/MK3 platforms, not a repurposed AR-15 part
Smoother cycling and improved reliability with .308 and other big-bore calibers
A carbine-length solution ideal for adjustable stocks and compact configurations
Durable, precision-made construction from a trusted AR manufacturer
A straightforward, drop-in component that helps your large-frame AR run the way it should
If you’re serious about building or upgrading a dependable AR-10–style rifle, the CMMG MK3 AR-10 Carbine Buffer Assembly is a foundational part of a reliable, well-tuned recoil system.
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