Don't arbitrarily substitute primers.
I can't remember which book it's in, but I recently re-read a chapter in one of my ballistics books detailing a fairly in-depth primer test with several 30 caliber cartridges.
By taking a known-safe load, and simply changing the primer, the author found that pressures could increase as much as 11,000 psi.
Most primer substitutions are fairly tame, but without good data, how are you supposed to know which primers will give you a significant pressure jump?
That is not something I
want to take a chance with.
(I want to say the book is Firearms Pressure Factors
, but that might only be on my mind because there was a piece on it in the current issue of Handloader