I bought a 189 series new, as soon as Ruger went from the 'long throat .308 bore' to the .310 in '92. did OK out of the box with good ammo after I filed the front sight to get POI right. some tweaking and an Eagle brake with the HK type front sight and it's doing very well. generally speaking magazines that are 100% are limited to 10 rounds (American and ProMag) but I have 2 USA 20's I tweaked to do 100% and CProducts is comeing out with 20 rd. if their usual quality is present they likely will be very good.
now I'll admit that my nephews early Chinese SKS with 4X scope shoots as good off the rest as my M30 with 1.5X4.5 glass. but they sure aren't the same rifle. the Mini is much better handling and with good aftermarket iron sights added IMO is better than the SKS with irons.
Ruger recommends brass-cased ammo and good reasonable priced ammo is available if you look for it. Lapua, Sako, Fiocchi, PP, Yugo mil-surp (corrosive but good shooting), PMP, IMI and others.
and in the caliber wars 150gr ammo is also available makeing the M30 an ideal black bear and wild/feral hog gun at relatively short (under 150yd) range. actually the twist rate favors the 150gr slugs as my handloads have done very well (all were compressed loads with 322 to get fps up I just got some 4198 to try). the M30 can take it with buffers.