Yep I use a piece of Masking Tape over the muzzle and have hunted a couple of stratght days in the pouring rain and it still went off just fine. It's Funny though I had to convince a few of My Hunting MLer Buddies that it was OK to use the Tape as they said I was going to Blow Up! HA HA! but after they backed up 50 feet and watched me fire a shot with it on, then reload and tape and shoot again I finally convinced them it was Safe.
My Wifes a Nurse and I had her bring some finger cots home from work and I gave em to My Hunting Buddies, the Tape was to much of a Hassle for them to cut and put on.
I cut pieces of Tape about the size of a quarter, clean the muzzle end and stick it on and press it around the barrel end, I never had one come off untill I fired.
(BP)