Do you mean they were really hard to fully seat, or they just wouldn't go in at all? I mostly use CCI primers, but just loaded around 800 .45acp LP using Federal, and every so often, I'd run into a case that didn't want to let the primer fully seat. I'd carefully but forcefully make them go in. This was mixed brass, primarily Winchester, RP, Federal, Speer, PMC, etc. I think most of the tough ones were actually Winchester. I haven't measured, but I suspect the Federal primers are just a tiny bit larger than CCI LP.
They fail to seat...you will crush the primer and it will still not seat. I never had this problem before, but then I haven't loaded a ton of .45's. Maybe this is the first time I've encountered the CBC brass. I am using the Dillon 650, mixed brass and Tula LP. At some point I may use other primers and see if they seat in the CBC brass.