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CMMG
Overview
The CMMG AR-15 Carbine Buffer Assembly is a crucial component of your AR-15 build, designed to work with Mil-Spec buffer tubes and optimized for carbine configurations. This assembly ensures smooth cycling and reliable operation by providing the necessary weight and recoil management for your firearm. It is commonly found in builds that utilize a mid-length gas system and chambered in 5.56 NATO, making it a solid choice for a variety of applications.
CMMG AR-15 Carbine Buffer Assembly - 55CA977 was the second most added buffer on GunPartPicker in August 2026, behind the Geissele Automatics Super 42 Braided Buffer Spring and H3 Buffer, with about 14% of all buffers added to builds. That's its 4th straight month at #2. Builds with this buffer are mostly chambered in 5.56 NATO (75%, then .223 Wylde 25%), mostly on mid-length gas (67%, then carbine-length 22%), and mostly AR-15 (74%, then AR-10 22%).
Availability is good: it was in stock at one retailer or another nearly every day in August 2026, and today 5 of the 7 retailers we track have it in stock. It dipped to $17.15 at Brownells for a stretch in August 2026, well under its usual $19.99, so sales do come around. Buying today, the lowest price is $19.99 at Sportsman Warehouse, above August's low of $17.15, so a better deal may come back.
Updated · from real builds on GunPartPicker · Prices checked · refreshed daily across 31 retailers
We ranked every buffer by how often it shows up in real builds on GunPartPicker.
Read the guide: AR-15 Buffer Guide →The part most often added in each category by the 511 builds that include this one
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Aggregated and anonymized data showing how builders use this product
Builds in the community that include the CMMG AR-15 Carbine Buffer Assembly - 55CA977
| Build | Parts | Total |
|---|---|---|
 | 23 | $2725.07 |
 | 15 | $1264.58 |
 | 28 | $3609.01 |
 | 31 | $7457.57 |
 | 29 | $1874.07 |
 | 22 | $3048.17 |
| 17 | $930.77 |
 | 35 | $3451.02 |
| 26 | $2048.76 |
 | 26 | $1819.82 |
 | 19 | $629.41 |
 | 27 | $901.33 |
2 global ratings
Top reviews
CMMG carbine buffer assembly works correctly. Inside weights dont rattle. Phosphate steel body wont show wear. Wish a spare detent had been included for the price. Otherwise function is what you need for any carbine cycling.
standard carbine buffer assembly from CMMG, comes with the buffer and rubber bumper. weight balance is correct for a carbine gas system. install is direct into a mil spec tube. cheap and reliable
