The 70% case volume thing with Titegroup sounds spooky... I've used 5 - 5.5 grains in .45 Colt cases and 3.5 grains in .357 cases for CAS loads for thousands of rounds with no problems. IMR's new Trail Boss powder will cure the case volume problem for CAS shooters when it hits the market. It's made very bulky to take up the case volume when using low charge weights like this.
Sometimes the squeaky wheel gets replaced...