I've been around and around with the slow and fast twist questions recently, playing with a 244 Rem (1-12"), a 223 (1-12), and a 222 (1-14). They really don't like long bullets.
I've also loaded for some fast-twist barrels, and found that they did just fine with bullets shorter than optimal for their twist rate. They did not produce benchrest match-winning accuracy, but nice groups of less than a half-inch.
Some rather clear reading on the "problem" of over-stabilization can be pursued at this link:
1-12 vs. 1-9 Twist in .223's While the topic is the 223, the generalizations are useful. (Apprropriately for this forum, the word "Bushmaster" is used toward the end of the piece, in which a 1-9 carbine does fine with short bullets.)
Back in the bad old days, bullets were not as well-made as they are currently, and "proper" twist rates were important. A batch of imperfectly balanced bullets would make a much wider group when spinning faster than needed for just enough stability. Now that bullets are better made, it's rare to get a batch that will open up a group if spun even much faster than needed for its length.
--Bob