Does p[rimer brand matter?

[Cossack]

I agree with the yes and no comment.
I generally do not find much difference in them when I work up the load with the same brand. But changing primers in a developed load can make a difference in group size.
They can also make a difference in gun function. I once worked up some loads in a 270 Encore that would not detonate with Federal primers. They did go off when I switched to CCI. Seems the Federals are not quite as thick as the CCI's, coupled with the light hammer strike of this gun, they wouldn't work. A friend found the same thing in a Marlin lever 45/70 he was loading using Federals.
Swithcing from small rifle primer to small pistol primer in my Hornet made a big difference in improved accuracy.
So, I guess the answer is: It all depends...which is just about on par for much of reloading/shooting.