I guess a better way to word my question would be if a load calls for hornady brass, could you use winchester or remington? Same thing with primers. If it calls for one, could you use another?
You could get into trouble substituting cases, expecially with heavy loads of powder. I do not re-load for the 7mm Remington Magnum and do knowtheweights of the various brands of cases. Before substituting brands of cases, weigh them first. Let's say that you worked up a heavyload for a thinner (lighter) case. That same quantity of powdercan cause pressure to go up dramaticallyif itisused in a thicker (heavier) case.
Isometimes substitute primers in my lighter loads but not in the heavy loads.