chaos accuracy system?

does anyone know the exact changes?

No, but it's rumored to be the same formula as BB only with a smaller level penalty - 2% is the most-heard number.

The actual accuracy formula requires more accuracy stat to reach 100% hit rate. No idea what the requirement is.

Can't say exactly what the new formula is, but, at level 42, my Gunslinger hits Dojo Dyle about 50% of the time, with 803 weapon acc.

That's with a 23 level gap - previously would have been 0% hitrate. If it's 2% per level then 54% hitrate matches decently with what I saw.