Originally Posted by Mule Deer
Now to address something that used to be true, but isn't any longer, at least with all the major brands of American primers I know of. Handling primers with your fingers has zero effect, because years ago manufacturers started sealing the priming compound with a water and oil-impervious coatiing. In fact you can soak 'em in water or even oil for several days, rub off the oil, and they'll still go bang. So no, there's no danger of turning a modern primer into a "dud" by handling it with your fingers.

IIRC, I read an account where a guy soaked primers in WD-40, loaded them and they all went bang...

DF