If it won't run in its original condition, then send it in to Ruger. I bought my Mini 20 some years ago used. Here awhile back it started to act up. Wouldn't cycle. I field stripped it, bought some factory ammo, tried OEM mag no go.
Sent it to Connecticut for about a month, she's good as new. They replaced bolt, gas block and piston. All it cost me was shipping. Ruger is a class act.