I did a search online and read that Dick Metcalf tried this and wrote an article on it in Shooting Times. I dug through my back issues and found the article in a 2008 copy of Best of Shooting Times and Guns&Ammo.

He tested the same bullet and powder charge in a Contender and a Blackhawk using 45 Colt and cut down 454 brass. He wrote that the 454 brass with rifle primers had increased velocity and accuracy. He didn't see any pressure problems in his tests.

He was using W296 in his comparison with 260gr Partitions. I noticed that the lowest charge he used in the Blackhawk was what Hodgdon lists as a max charge (of H110) for that bullet. The heaviest charge he tested as 1.5gr beyond that.

That sounds promising since I wouldn't plan to load anywhere near max charges. Still not sure if I'm going to try it.