The HC (Hearthco) moons work best with Remington and Starline. Some Federals work fine but others are too tight. Don't even try to put Winchester brass in the Hearthco clips for the 627. The Hearthcos are a little pricy but they are the best and I use only HC moons in competition.
SW357 Addict: Let us know how many rounds it takes for the C&S extended firing pin to break. Keep your original pin handy.
If the C & S firing pin is fit properly, there should be no issues with breaking. I've got over 5000 rounds and countless dry-fires with one on my 625and still going strong.