The biggest POS that I've ever had the misfortune to own was a Mini 14 SS Ranch Rifle. A 6" pattern at 100 yards with a scope was cause for celebration. All of the "tricks" were tried to improve the groups, i.e. muzzle brake, torque the gas block, etc. Nothing helped this excuse for a rifle. It was gone in a heartbeat.
I now have AR 15s with 16" bbls and 20" bbls. As far as accuracy, I've not yet seen a Mini that will outshoot any one of them, even the 16" rifles are more accurate.
Fast forward a bit. Two of my friends bought Minis, one a 14 and the other a 30. Neither one of those rifles shot worth a darn. Both wore scopes during accuracy testing. They too dumped the Minis and went to AR-15s. They are both happy with their new rifles.