Has anyone tried this? The only issue I can think of would be a possible pressure increase from using SR primers instead of a LP primers. Is there anything I'm overlooking or reasons not to do it?

I'm not interested in "hot rodding" my 45 Colt Blackhawk. I have 454 Casulls for that. What got me thinking about it is that I have enough new 454 Casull brass to last me a long time. With some hand issues I don't shoot 454 Casull as much as I used to. That got me thinking about using 454 brass in the 45 Colt.