oldarmy said:All of these answers are correct.
I shoot my black powder weapons... both rifles and pistols allot during the GOOD weather in northern NEW HAMPSHIRE. In the winter.. I will clean and use a heavier oil to prevent rust.
The old advise about Oil and BP not mixing is only some what true.
You need to oil your weapons,,clean them before shooting :v
Oil used as a preservative is different than using it as a patch lube.
Anyone concerned about petroleum used as a preservative can wash it out with a little denatured sloshed around the bore then dry the bore and load.
Alcohol almost always contains some water so it needs to be wiped dry.
This is not as important with a plain breech gun as a patent breech. IF the breech is installed properly.
It is also important with most "factory mades" since they almost always have a fouling/oil trap in the breech end due to a poorly fit breech plug.
Oil trapped in gaps can soak into the powder.
Dan