The barrel twist on the current Mini 14s is 1-9. That is ideal for a bullet the length of the 62 gr SS109 (0.911") and M855 (0.907") projectiles.

1-9 twist will shoot any lead core bullet up to 68 grains well and it will also shoot 55 gr boat tailed FMJ and spire point bullets well. In particular the .735" long Hornady 55 gr FMJ shoots very well in 1-9 twist barrels as it is longer than the average 55 gr bullet and is well made and more concentric than many FMJs.

The factory accuracy standard for the 58X series Mini-14s is 2 MOA, and many will do a bit better than that without any additional work.