Born on date?

[BananaDoc]

I am looking at a M 640 in .38 spl. only with a serial number of BKN4084. I thought I would asked our Best and Brightest if there was way to tell the age? Also, these are +P rated correct?

Many thanks!
(and sorry about the Nixon reference... )
DOC

 

[PMRet]

Based on the serial number, SWCA dates your gun to 1991. And yes, it should be fine with +P ammo.