Mossberg 800a Serial Numbers -

| Serial Number Range | Approximate Year | Notes | |---------------------|------------------|-------| | 1,000 – 15,000 | 1967 – 1968 | First year production. Often have “Micro-Groove” style rifling (borrowed from Marlin design). | | 15,001 – 35,000 | 1969 | Transition year. Some parts (safeties, triggers) show minor revisions. | | 35,001 – 55,000 | 1970 | Peak production. Most common in the used market today. | | 55,001 – 70,000+ | 1971 | Final year. Discontinued in 1971. Rifles near 70,000 are rare. |