6.5 twist shot down to 52 bthp matchkings just fine for us for years.
That said, I don't use light bullets... 68/69 typically are the lightest cup and core... TSX type bullets I"ll drop back to 55ish if I can't find 62s...
77bthp matchkings and 75 bthp hornady have never failed to kill anything I've shot at. But be aware they are not a hunting bullet, fwiw. And I"m what I like to think of as above average at trailing... plus have a dog now that takes all the fun out of looking for deer, other than seeing how happy he is and making shorter work of finding dead/wounded ones...
