This is CMMG's factory action spring for Mk3 rifles. The action spring sits in the buffer tube behind the buffer and drives the bolt carrier forward after each shot. Replace it when it weakens to keep cycling reliable. It is a genuine CMMG part.
- Fits: CMMG Mk3
- Type: action (buffer) spring
- Manufacturer part: 38CA9EB
- Brand: CMMG
- Genuine CMMG factory part
