Most people put some type of rubber covering over the end of the barrel. I use "muzzle mitts", but others use small ballons or finger cots (available at any drugstore). You do not need to remove these to shoot, just shoot through them.

For the breech, I have never used a bolt action. There are some things that wrap around and protect this area. Seems like some people even use saran wrap. However, in some states, the breech must be open to the weather, so check your regs. Never leave anything over the barrel end or breech overnight if possible because they will hold moisture against the barrel and tend to cause rusting faster. Every night I remove them and apply oil to the barrel as needed.