It's the barrel that's crap. When it heats up the bullets go flying every which way. The problem is that in South Texas it is always hot. I can barely get two bullets to group, and if I get three it's time for a party. God knows where the bullets go after 150 yards.
I have several friends who had their Mini-30 and Mini-14 rifles re-barreled and the rifles were turned into accurate, useful firearms. It's just a shame that you have to spend $500 on a brand new rifle and then toss in at least that much more to make it accurate.
No business for Ruger from me.
Before you try a new barrel test to see if the gas port fitting is too tight. A gunsmith can do that fairly quickly. Also have him check the bolt fit. A new barrel does usually solve it but I have seen ones that the throat/bolt fit were so bad ...you get it.