CMMG Receiver Extension and Stock Kit – Carbine, Mk3
Upgrade your large-frame AR platform with the CMMG Receiver Extension and Stock Kit for Carbine-length Mk3 rifles. Engineered for durability and performance, this complete kit includes everything needed to finish your lower receiver build or enhance your current setup.
The CMMG Mk3 Receiver Extension and Stock Kit is a premium solution for your AR-10/.308 (DPMS Gen 1 pattern) or Mk3 build. Whether you’re replacing worn components or completing a custom rifle, this drop-in kit provides the reliability, fit, and finish that CMMG is known for.
Designed for carbine-length buffer systems, it includes the receiver extension (buffer tube), carbine buffer, buffer spring, castle nut, end plate, and a collapsible stock, all precision-manufactured to CMMG’s military-grade standards.
Key Features of CMMG Receiver Extension and Stock Kit – Carbine, Mk3
✅ Complete Drop-In Stock Kit
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Includes mil-spec diameter buffer tube, stock, spring, buffer, castle nut, and end plate
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Everything you need to complete your Mk3 or AR-10 lower receiver
✅ Designed for AR-10 / Mk3 Rifles
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Compatible with CMMG Mk3 lowers and most DPMS Gen 1 pattern AR-10 platforms
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Perfect for large-caliber builds like .308 Win, 6.5 Creedmoor, and more
✅ CMMG Quality Engineering
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Manufactured in the USA with military-grade materials
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Backed by CMMG’s proven reputation for reliability and performance
Technical Specifications for CMMG Receiver Extension and Stock Kit – Carbine, Mk3
| Specification | Detail |
|---|---|
| Manufacturer | CMMG Inc. |
| Model | Receiver Extension and Stock Kit, Mk3 |
| Platform | AR-10 / .308 / Mk3 (DPMS Gen 1 pattern) |
| Buffer System | Carbine-length |
| Stock Type | Collapsible / Adjustable |
| Tube Diameter | Mil-spec |
| Includes | Stock, buffer tube, buffer, spring, hardware |
| Material | Aluminum, steel, high-impact polymer |
| Finish | Hardcoat anodized (tube), matte black stock |
Why Choose the CMMG Mk3 Stock Kit?
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Built for Bigger Calibers – Designed specifically for large-frame AR platforms
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No Guesswork – Comes with everything needed for a buffer assembly
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Reliable Performance – Tuned to ensure smooth cycling and recoil control
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Made in the USA – Trusted by shooters for duty, defense, and competition
FAQs
Q: Will this fit my standard AR-15 lower?
A: No, this kit is designed for larger frame rifles like the CMMG Mk3 and DPMS Gen 1 AR-10 pattern lowers.
Q: Is the stock mil-spec or commercial size?
A: The buffer tube is mil-spec diameter, compatible with most aftermarket mil-spec stocks.
Q: What length buffer system is this?
A: It uses a carbine-length buffer system appropriate for AR-10/Mk3 platforms.
Building a .308 AR or upgrading your Mk3?
Trust the CMMG Receiver Extension and Stock Kit to deliver military-grade performance and a perfect fit—right out of the box. Everything you need for a smooth, solid stock assembly.
Add it to your cart now and complete your next AR-10 build with confidence.
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