JIM BOB:
The 627-5 Performance center guns were manufactured in 2003 & 2004, per Standard Catalog of S&W, but they are also a cataloged item today. The BCFxxxx serial range would have been used in 1989, if used in sequence. I can only assume that the BCF range is was reserved for the performance center. To get a proper shipping date for your gun you would need to contact Roy Jinks at S&W and pay a $50 fee. Otherwise 2003-2009 is as close as I can give you.
The 686-5 was introduced in 1997 and replaced by the 686-6 in 2001. The serial number ranges for this period given in the standard Catalog of S&W all begin with C, in fact the C prefix was still in use in 2004 when the serial ranges recorded end, so again 1997-2001 is the best I can give you.