In these straitened times, I have made some substitutions in reloading; mostly 9mm for IDPA and USPSA. I found little to no difference in velocity by changing primers, SP, SPMag, SR of whatever brand I had.
BUT CCI BR4 small rifle match was notably hard to seat; I resorted to hand seating, much as I dislike going de-progressive. I figure they are not only alleged better QC, they are likely stiff AR cups because a major application would be High Power.
They have all thus far went off in hammer fired 9mms, though.