From Shotgun World "The 109 CCI's are the same as 209 CCI's. the difference is that one is plated, and the other is not. Originally done to make the unplated one cheaper." In my experience loading over 100K shot shells with 209's primers is the actual diameter of the primer off the top of my head 209's CCI, WIN, and FED's are .235 some of the European are about 100K over so it the fit and go bang your good.