I noticed this guy is doing well with a 1:8 shooting 55g at 500-600m. Rabbits and fox.223.
I think 1:9 is the best as sometimes a 1:9 cz will shoot 40g well and even 75g from my experience.
I think the 53 vmax likes a 1:10 barrel best and the 53's are excellent all round bullets. So a 1:9 should handle the 53 vamx well.
but its not set in stone. and people get lucky and unlucky.
i think where your coming from is if you want to shoot 40g all day long its best to get a 1:12 1:14.
but if you want something versatile that has a best chance of handling say 50 - 69g 1:9 is best.
maybe 1:8 handles 53 - 75 best.
you pays your money and takes your chances