Do some research when buying after market mags for a mini 14 many are junk.
I know. Iv'e got two good twenties, one good out-of-the-wrapper 30, one thirty that required a little creative bending and filing, and one thirty that is an absolute P.O.S.
Side note: I found the 20s at Aaron Tippen's gun shop in Smithville, TN. Neat place. Buy guns and ammo in the back, beer and snacks up front. Unfortunately the "Honky-Tonk Superman" wasn't there to autograph them.