I just joined this forum when I became interested in buying a mini 14 and had trouble learning which one to buy. Did discover that I should be looking for a 581 series over a 580 series but hard to tell what series a mini is by looking at it. I think I've come a little closer in determining the years the series started diverging and came across this on the Ruger site to tell what year a mini was made according to it's serial number. Looks like any with the 580 in the first numbers where the 'New Series' or 581 series which are more desirable. Hope this info helps others and that it's not a repeat that can be found elsewhere here but I couldn't locate it. Roy Directly from the Ruger web site.

------------------------------------------------------------- Mini-14 Rifle (Manufactured from 1974 to 1977) Caliber:.223 Rem. Beginning Serial Number: Years of Production: 180- 180- 180- 180- Beginning Serial Number: Years of Production: 181- 181- 181- 182- 183- 183- 184- 184- 184- 185- 185- 185- 185- 186- 186- 186- 186- 186- 186- 186- 186- 186- *196- *196- *196- *196- *197- Mini-14 Ranch Rifle (Manufactured from 1982 - 2004) Caliber:.222 Rem.,.223 Rem. Beginning Serial Number: Years of Production: 187- 187- 187- 187- 187- 187- 187- 187- 188- 188- 188- 188- 188- 188- 195- 195- 195- 195- 196- 196- 196- 196- 197- New Mini-14 Ranch Rifle Caliber:.223 Rem. Beginning Serial Number: Years of Production: 580- 580- 580- 580- 580- The above chart shows the approximate first serial number shipped for the indicated year. This number should be used as a point of reference only. It is not necessarily the very first serial number shipped, but it can be used to determine the approximate year your Ruger firearm was shipped.

Ruger Rifles Serial Numbers by Year for Ruger Rifles 1961 thru 1993. Click Here for Ruger's 'Caliber and Serial Number History' Page! Running a close second in popularity to 'When was my Ruger made? How To Install Rapelay Mods on this page. ' Ruger Rifles Serial Numbers by Year for Ruger Rifles 1961 thru 1993. What is manufacture date of Ruger rifle 77047911? What is manufacture date of ruger pistol 85. What is date of manufacture for Ruger rifle serial number 75.