Pull the primer as previously stated. That being said, I also leave the gun loaded.

I have experienced a misfire in my MZ. It was late season in Michigan and about15 degrees out. After the evening hunt I brought the gun inside and left it near the door for the next morning hunt. I did not see any deer that morning, but wanted to fire the gun. It misfired. I believe this was because of the condensation the forms when bringing a cold barrel into a warm environment. I wiped off the outside of the gun when the condensation appeared, but did not think about the inside of the gun and how this might affect the powder. I now leave the gun in the garage so it can remain cold and not worry about the condensation.