The mini-30's like American made brass case ammo. Close to 100% reliability with those. The reason I say close is with factory mags it is 100% but the poor quality of aftermarket hi caps is very poor and you will need a few to find one that works reliably. Back in the day when Ruger would not sell hi-cap mags for the Mini's it sucked. At least now you can buy factory 20 rounders.

Now with steel case com block ammo reliability is poor. This can be easily fixed with a Wolff heavy duty hammer spring. The com block primers are too hard for the factory spring.

Anything else you'd like to know?