CMMG Inc Spring Action Carbine AR-15. CMMG constructed these AR15 Buffer Springs for use with your lower receiver. The CMMG Inc Carbine Buffer Retainer Spring delivers quiet and smooth operation for success with every shot. Get the CMMG Inc AR15 Carbine Buffer Spring for your weapon customization needs. Specifications for CMMG Inc AR-15 Action Spring Carbine: Manufacturer: CMMG Gun Model: AR-15 Gun Type: Carbine Condition: New Package Contents: CMMG Inc AR-15 Action Spring Carbine The CMMG Inc Carbine Buffer Spring is a quality addition to the CMMG lineup. For more great deals on AR15 Buffer Springs by CMMG please browse our CMMG Inc Gun Parts page. What firearm models does the manufacturer say CMMG Inc AR-15 Action Spring Carbine is compatible with? The manufacturer suggests that CMMG Inc AR-15 Action Spring Carbine is compatible with AR-15CMMG Inc Carbine Buffer Spring - 55CA9A2