[mountainlion]

WD 40 won’t cut the copper or lead in the bore. It is mostly kerosene and the lube is just temporary. It should do a fair job on the powder residue so go for it.

[Eric in the Ozarks]

The local gunsmith here advises not to use WD 40. Claims its gummy. I use Hoppes exclusively.

[Daffynition]

FWIW WD-40 does not contain kerosene according to the WD website.

Owl_Eagle, if this is a one-time deal/emergency, I wouldn't worry. But for regular cleaning, I'd stick to the "good stuff."