I shoot mostly traditional sidelock muzzle loaders in both flint and percussion. I participate is winter shoots throughout New England. I have found that oil, and some greases tend to stiffen up and slow down the fall of the hammer resulting in slight delays of ignition. In the past years, I have taken the locks off the guns I plan to shoot, de-grease/oil them with auto carb cleaner, then lube the lock with powdered graphite. Graphite doesn't freeze or stiffen up, so I have quicker lock times that can make all the difference in some shoots.