I have 2 Ranch Rifles and another Mini 30 and all are accurate. The Mini 30 is probably the least, but look at the round. No problem taking deer at 150 yds. The 2 Mini 14’s are VERY accurate. If you are experiencing problems, maybe have a look at a defect in the stock. I have them scoped with 3x9’s( cheap) and they can hit a quarter at 100 yds, certainly no more than a silver dollar with bench rest at 100yds. I’ll bet a gun shop could find something and fix it cheaper than a new bull barrel bought and mounted. The way the action fits in the stock along with the trigger box is critical and I was told not to keep disassembling it by more than a few. I was told back in the Army not to take my M-14 apart very much. It seems to loosen the action in the wood to do that.
My Mini 14 is probably 2.5 inches at 100 yards. Other guns are .75 inches at 100 yards so it is not me. Still not terrible so considering cost to improve.