Just keep in mind the 71gr copper rose needs a 7 twist barrel so if you ever plan to go out of state you will risk jacketed lead bullets coming apart with high RPMs from a 22cm. You could do a 7.5 or 8 twist and shoot the 79gr DRT or a lighter Hammer in CA. If the gun is only for CA and copper monos, 7 twist 22cm is great.
The 6cm gives a bit more forgiveness in that regard if you do want to go out of state with it. A 7 twist allows you to shoot the 100gr PVA, 93gr McGuire, 89gr Apex, etc. and also shoots the heavy 6mm lead bullets at a lower velocity than the 22cm, thus lower RPMs. The 93gr McGuire might also work in a 7.5tw depending on DA. The 6mm also gets you past any 22 caliber restrictions out of state.