That mold is for a 500 S&W Magnum!
If you are planning to load to magnum velocities, I suspect you will get better results with a gas check.
I tried 30 caliber bullets without gas checks and they shot just awful. I was pushing them around 1700 fps. Gas checks brought them back.
I believe that if you push a lead bullet with a naked gas check base too hard, you deform the already wonky end.