Keep your rifle running reliably with the CMMG AR-15 Extractor Spring and Buffer Kit – Part #55BA42D (UPC: 810046232187). This small but critical component kit is designed to restore or upgrade the extraction system in your AR-15 bolt, improving reliability, especially in high-round-count, rapid-fire, or dirty operating conditions.
If you’re chasing consistent extraction, fewer stuck cases, and smoother cycling, this CMMG extractor spring and buffer kit is an inexpensive, must-have upgrade for any serious AR-15 owner, builder, or armorer.
Designed to Improve AR-15 Extraction Reliability
The extractor assembly is one of the hardest-working parts in your AR-15 bolt carrier group. Over time, factory extractor springs can weaken, leading to:
The CMMG AR-15 Extractor Spring and Buffer Kit 55BA42D is engineered to restore proper spring tension and support for the extractor, helping your rifle pull spent cases cleanly from the chamber and eject them with authority.
Quality Components from a Trusted AR Manufacturer
CMMG is known for its high-quality AR-15 rifles, parts, and accessories, and this kit is no exception. It provides:
Extractor spring – tuned for reliable tension and long service life
Rubber/insert buffer – supports the spring and fine-tunes extractor pressure
Built to Mil-Spec-style dimensions for broad compatibility with standard AR-15 bolts
This kit is ideal for replacing worn or lost extractor parts, or for upgrading an older rifle that’s starting to show extraction issues.
Perfect for Maintenance, Repairs, and Spare Parts Kits
An extractor spring is a wear item, and having a replacement on hand is smart preventive maintenance:
Great for routine bolt carrier group rebuilds
Essential for range and duty spares so you’re never sidelined by a simple spring failure
Smart addition to your field repair kit, range bag, or armorer’s toolbox
If you shoot frequently, especially with high round counts or dirty ammunition, keeping a CMMG extractor spring and buffer on hand is cheap insurance.
Compatible with Standard AR-15 / M16 Style Bolts
The CMMG Extractor Spring and Buffer Kit 55BA42D is designed for AR-15 / M16 pattern bolts in common calibers like 5.56 NATO / .223 Rem (and many other standard small-frame variants that share the same extractor design).
Always verify compatibility with your specific bolt and caliber, but for most standard AR-15 builds, this kit drops right into the existing extractor assembly.
Easy Installation – Drop-In Replacement
Installation is straightforward for anyone familiar with AR-15 bolt carrier group disassembly:
Remove the BCG from the upper
Disassemble the bolt and extractor
Replace the old extractor spring and insert with the new CMMG spring and buffer
Reassemble and function-check
With basic tools and a few minutes of work, you can significantly improve the reliability of your rifle’s extraction system.
Key Features – CMMG AR-15 Extractor Spring and Buffer Kit 55BA42D
Brand: CMMG
Product: AR-15 Extractor Spring and Buffer Kit
Part Number / SKU: 55BA42D
UPC: 810046232187
Includes: Extractor spring and insert/buffer
Platform: AR-15 / M16 style bolt carrier groups
Purpose: Replace or upgrade worn extractor components for more reliable case extraction
Ideal for These Shooters & Use Cases
This CMMG AR-15 Extractor Spring and Buffer Kit is perfect if you:
Own one or more AR-15 rifles and want to improve or maintain reliability
Shoot a lot and want to replace tired extractor springs before they cause problems
Build and service ARs and need quality, branded replacement parts
Want a compact, affordable spare part to keep in your range bag or field kit
From home defense to training classes and competition, a strong, properly supported extractor spring is critical for keeping your rifle running.
If you’re serious about AR-15 reliability, the CMMG AR-15 Extractor Spring and Buffer Kit 55BA42D (810046232187) is a simple, high-value upgrade that can make a big difference in performance.
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