CMMG AR-15 Carbine Action Buffer Spring - 55CA9A2
Click to see full view
CMMG
Overview
The CMMG AR-15 Carbine Action Buffer Spring is designed specifically for carbine-length systems, providing the necessary tension to ensure reliable cycling of the action. Made from steel, this buffer spring contributes to the overall durability and performance of your AR-15 build. It is commonly found in builds utilizing a mid-length gas system chambered in 5.56 NATO, making it a solid choice for those configurations.
Specifications
Available Merchants(7)
Prices checked
Price Alert
October 2026 on GunPartPicker
CMMG AR-15 Carbine Action Buffer Spring - 55CA9A2 ranked #14 of the 52 buffer springs builders added on GunPartPicker in October 2026. Builders have added it to their builds on GunPartPicker. Since April 2026, it ranks #18 of the 116 buffer springs builders have added. Builds with this buffer spring are mostly chambered in 5.56 NATO (78%, then 300 Blackout 17%), split between mid-length (58%) and carbine-length (17%) gas systems, and nearly all AR-15.
Availability is good: it was in stock at one retailer or another nearly every time we checked in October 2026, and today 6 of the 7 retailers we track have it in stock. It dipped to $4.98 at Classic Firearms for a stretch in October 2026, well under its usual $9.99 to $13.99, so sales do come around. Buying today, the lowest price is $4.62 at Classic Firearms, which matches the best price we saw in October.
Updated · from real builds on GunPartPicker · Prices checked · refreshed daily across 37 retailers
Not sure which buffer spring to pick?
We ranked every buffer spring by how often it shows up in real builds on GunPartPicker.
Read the guide: AR-15 Buffer Spring Guide →Check it against the live catalog:
Frequently Built With
The part most often added in each category by the builds that include this one
CMMG AR-15 Carbine Buffer Assembly - 55CA977
CMMG AR-15 HD Pivot and Takedown Pin Parts KIT - 55AFF3B
Rise Armament AR-15 Magazine Release Button - Rise Red
Bravo Company AR-15/M16 BCM Mil-Spec 6 Position Receiver Extension
Phase 5 Tactical Extended Ambidextrous Bolt Release V3 - Red Cerakote
Smith & Wesson Sw M&P15 Stripped Lower Receiver 5.56mm
Build Configuration Breakdown
Aggregated and anonymized data showing how builders use this product
PlatformBased on real build data showing which platform (AR-15, AR-10, AR-9) builders pair with this product.
CaliberBased on real build data showing which calibers builders choose alongside this product.
Gas SystemBased on real build data showing which gas system lengths builders use with this product.
Builds Featuring This Part
See all builds →Builds in the community that include the CMMG AR-15 Carbine Action Buffer Spring - 55CA9A2
| Build | Parts | Total |
|---|---|---|
 | 20 | $1640.17 |
 | 19 | $1476.68 |
 | 28 | $2313.71 |
No reviews yet. Be the first to review this product!