They are hotter. Depends on how fast or slow burning your powder is. I've done it in .223 with CFE-.223 and was fine... also with H4895 with not so great of results. I didn't lose parts off my gun or anything, but it was too quick of a pressure curve to handle it. Obviously the prudent thing is to back off a little and work back up.

What powder? Stick vs. ball powder can also be a thing.