If Vapodog is pushing the bullet 3700+ with a 1:14 you should be able to get well above 3400 with 1:12. Centripetal force would be causing factor with the bullet rupture. The added twist is a difference but not extremely substantial. I'm sure it could be calculated, just don't know the failing point? It will be easier to experiment with it. Let us know how they do!!!![>:]