If you think grease is still in the barrel and you have access to some disk brake cleaner, throttle body cleaner, acetone, MEK or lacquer thinner pour some down the barrel and scrub the bore with a soaked cleaning patch.
Make sure some of the fluid passes thru the flame channel that connects the nipple or flintlock vent with the bore.
Do this outside, far away from any source of sparks or flames and don't breath any more of these solvents than you have to.
Make sure some of the fluid passes thru the flame channel that connects the nipple or flintlock vent with the bore.
Do this outside, far away from any source of sparks or flames and don't breath any more of these solvents than you have to.