I still load for a buddy with a 24" barrel .444 from the early 70's. It will not stabilize anything above 265-270gr. My 77/44 with a 1:20 twist shoots 300gr bullets quite well. I'd put a pretty good bet down that a 330gr bullet would absolutely need a 1:20 to stay point on.With the older 1-38" twist I could not get enough velocity to stablize.
If you have a legitimate reference, and BTB is unlikely to publish an irresponsible one, you are in a good place to stay within the window specified, and outside that, you are on your own.