Well said BAR, I would strongly discourage using imprpoer primers. Years ago I experimented with changing primers (3 differrent types of large rilfe primers)in a .270 whilst leaving all other components the same. There was a rather significant change in velocity from one type of primer to another; as velocity and pressure are directly linked there would have been distinct differences in pressure.

Use the right primer for the job and even if you change one brand of primer for another use due care.