In which gun?

When in doubt use a mag primer that fits your rifle the best but in my guns (Knights) even the mildest primers work fine because all the needed modifications (Lehigh) have been applied. Even WinT7s ignite BH209 with authority in mine and are spotless when removed.

I would get some Win209s (might be tight in a T/C) and get one of the mag primers too. I prefer the Fed 209A over the CCI209M just because it fits mine better and come out much cleaner in the Lehigh NFPJ.