ORIGINAL: Breechplug
For all the actions on my guns I use ( Molly Lube ) it's a (Dry Film Aerosol Lubricant) you cant beat this stuff. Have you or anyones else used it? I learned a-long time ago that WD-40 will gum up and freeze. I had it applied to a shotgun's action and fireing pin. Well that day it was zero out and along came a nice buck. I aimed, pulled the trigger and nothing! The WD-40 froze solid and the fireing pin would'nt move. So from then on I never used it on actions, but have used it inside barrels.
wd-40 is about best you can put in your bore to displace water.
then dry itout with patch on your jag.
THEN use your oil of choice in bore.
i agree with wd-40 is not good like on fireing pin or action.
a lot used BREAKFREE CLP at skeet shooting on their actions and they know what is best there for that.
but they dont use it in bore of their shotguns.