A couple ways. The newer Mini-30 is not available in blue/wood configuration, and has a newer front site, rounded receiver edges, and has serial numbers starting with “581”. The 580 is the newer Mini-14. Ruger did a major retooling in 2006, and these changes reflect the newer design, along with better construction tolerances. Accuracy is suppose to be significantly better, and I believe this to be so.
The knowledge base on FR is amazing.
It’s still possible to destroy the accuracy of even the newer Mini’s. The four 10-32 screws that hold the gas block can be tightened enough where they will squeeze the barrel. Those four screws can only be snugged to 14 inch pounds and then red LOKTITE-ed.
I spent a couple of years off and on trying to correct the accuracy of the Mini. I even had an article half written for publication. It simply didn’t work. The earlier barrels just are not machined correctly to give good performance after the barrel heats up.
The Mini need a heavier barrel, an attachment point on the stock at the gas cylinder and a redesigned gas cylinder collar on the barrel.
The Mini and the .30 Carbine share the exact gas system but the lighter caliber in the carbine didn’t cause the problems like the Mini.
Thanks a lot for the info. Seems like the couple hundred for the new version may be money well spent.