Same size, but “weaker”
For light loads with fast powder
Not interchangeable across the board
Not a lot of load data for the regular CCI 209s comparatively Detailed Description
CCI 209 Primers (1000/box)
CCI 209 primers are for field and target loads in all gauges. Modern, non-corrosive, non-mercuric primer compounds for clean, sure ignition.
CCI makes two shotshell primers to cover your needs. CCI 209 primers are for field and target loads in all gauges. The CCI 209M is a true Magnum primer designed for heavy charges of slow-burning propellants. That makes the 209M a superb choice for waterfowl loads. Both use modern, non-corrosive, non-mercuric primer compounds for clean, sure ignition.
CCI 209: field and target loads
CCI 209M: heavy waterfowl and turkey loads

Part # 209 Primers Type & Use: Box/Case Diam.
#F616 Fiocchi 616 multi-purpose 209 1000/5000 0.242″
#RIO209 Rio 209 multi-purpose 209 1000/5000 0.245″
#CH209 Cheddite 209 multi-purpose 209 1000/5000 0.242″
#CCI CCI 209 small-bore & mild 1000/5000 0.241″
#CCIM CCI 209 Magnum magnum 209 uses 1000/5000 0.241″
#209A Federal 209A multi-purpose 209 1000/5000 0.241″
#R209 Remington STS multi-purpose 209 1000/5000 0.241″
#W209 Winchester 209 multi-purpose 209 1000/5000 0.241″

What is the harm if I use CCI 209 primers instead of Win 209 like the reload data calls for. I use CCI primers in all of my brass cartridge reloadings. A while back I was at the store to pick up some handgun primers and also picked up a sleeve of CCI 209. I did this without referring to any reload data, the only thing I knew was that I would need 209 primers.

CCIs are still slightly oversized so the pocket is only fit for more CCI primers. That was the story 30 years ago, anyhow. The deal then was to use CCI primers only in worn-out cases and leave them on the skeet range.