fire forming brass

I’ve got 2 new Sherman’s to form brass for, a 25 and a 6.5. I’m planning to use the COW method. I have a bunch of Universal Clays powder I won’t mind burning up. Is it fast enough? Hate to burn up precious pistol powders for this job. Starting load suggestions? (unless I’m completely off track...

Does anyone have load data to fire form 30-06 brass to 35 Whelen? I've checked the forum and haven't found a load data posted. Any help will be greatly appreciated! Thanks!