Funny stuff. I run a tapcon down the muzzle coated with permatex rtv. Seals out all the water and I remove it at the end of the season. Too bad I haven't found anything to shoot at in the last 30 years, so I don't know if it hurts accuracy.
On my mini 14 I just take about 10 wraps of duct tape and leave the roll attached to the end of the barrel to improve harmonics. I can't tell if it helps because everyone knows you can't hit the broad side of a barn with a mini while standing inside the barn. I use camo duct tape for that tactical look.
Truthfully I did take a spill once and plugged the barrel of a 6mm with mud (no rod with me). Had to use 6mm twigs and river water to wash it out. I was wishing for some tape that day.
