I'm not a rifle guy, but I can tell you what I saw. I had a Mini 14 purchased in 1976. Have no idea how it grouped beyond "minute of feral dog's ribcage." Sold it many years ago. I was at a LE rifle class a couple of years back. Everyone had AR type guns except 3 deputies from a nearby agency with Mini 14 W/3 shot burst selectors. Each day, we would check zero on the gun. The AR's seldom needed much change, even with wind and light variations. The Rugers? Well, sometimes they would not zero because the rear sight would not adjust enough to bring them to dead on, necessitating Kentucky windage. Each night, everybody cleaned their guns. Next morning, check zero. Again, no adjustments on AR's, but I saw the Ruger's points of impact shift from two to EIGHT inches, just from disassembly and cleaning. This was all 100 yard, prone, loop sling shooting. The instructor, who has taught lots of classes, said this is common for the Mini 14's and will not own one.
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When the wicked spring as the grass, and when all the workers of iniquity do flourish; IT IS that they shall be destroyed forever...Psalms 92.7