I've switched primers (Fed, Rem, Win, Fioch, Active, Ched, etc) in shotshell target loads without any harm. Was there a difference? Probably, but not that I could notice while firing. I used whatever I brand was the cheapest at the time.

That being said, however, the Win 209 primers seem to be a little bit undersized. After a few firings, especially after using another brand primer in that particular hull first, some primer pockets were loose enough that the primers would fall out when fired in a semi-automatic. Because of this, I tried to stay away from Win 209's altogether.