Both will stabilize a 220 at those velocities but the 9 will do it better. Will the 10 suffer in comparison? Probably not enough that one could tell on paper. Might be easier to find a 10 twist barrel on the shelf.
Both will stabilize a 220 at those velocities but the 9 will do it better. Will the 10 suffer in comparison? Probably not enough that one could tell on paper. Might be easier to find a 10 twist barrel on the shelf.
I have been looking into this recently as well, because I'm gathering parts as I can to do a 300 norma build also. I ended up ordering a 10 twist because that was the fastest twist rate in stock at otm tactical. Not sure if you're needing the barrel right away, but if you are the 10 twist barrel will be easier to find as spife stated.