It's not the bullet weight that is tied to barrel twist, but bullet length. Generally heavier means longer and a faster twist works better with longer bullets. But there are exceptions. Because of many factors one companies 180 gr bullets may be longer than another companies 180. A 180 pointed bullet and 180 round nose will have very different lengths with very different amounts of the bullet actually in contact with the barrel as the bullet moves through it.
There are no rules written in stone about bullet weight and barrel twist. Only general guidelines.