I use a solid aluminum range rod unless I'm in the feild. While I try not to rub it against the inside of the muzzle it sometimes happens. I usually just use my left hand to help guide it into the barrel to minimize any contact. The steel of the barrel is much harder than the ramrod so it is unlikely to do any damage if it litely touches from time to time. After many, many hundreds of rounds plus cleaning I have not noticed a problem.

If you are worried about it though, you might look into getting some heat shrink tubing that is just a bit larger than the rod and use a paint stripper heat gun to shrink fit it to the rod to give you a bit of cushioning for the inevitable rub against the muzzle. Most hardware stores and electronics stores should have heat shrink tubing in 4' lengths. Also, some hair driers may get hot enough to shrink it if you don't have a paint stripper. Could probably do it over the stove also.